Information recording method and information reproducing method

ABSTRACT

With this invention, at least one of a video file containing video information, a still picture file containing still picture information, and an audio file containing audio information and a management file having management information on a control method of reproducing the information in the file are recorded on an information storage medium. This realizes a data structure that causes the recording and deleting places on the information storage medium to correspond spuriously to places on a single tape, such as a VTR tape. Use of the data structure provides users with an easy-to-use interface.

BACKGROUND OF THE INVENTION

[0001] This invention is concerned with the improvements in and relatingto an information recording method of recording video information on aninformation storage medium and an information reproducing method ofreproducing the video information from the information storage medium,and more particularly to those suitable for a case where the videoinformation recorded on the information storage medium is the digitalvideo information compressed according to the MPEG (Moving Picture ImageCoding Experts Group) standards.

[0002] In recent years, systems for playing back an optical disk onwhich video (or moving picture) information and audio information havebeen recorded have been developed. They have been widely used in theform of, for example, LDs (Laser Disks) or video CDs (Compact Disks) forthe purpose of reproducing movie software or karaoke.

[0003] In this connection, the DVD (Digital Versatile Disk) standardemploying the internationally standardized MPEG-2 scheme and the AC(Audio Compression)-3 or other audio compression schemes has beenproposed. The DVD standard covers playback-only DVD video (or DVD-ROM(Read-Only Memory)), write-once DVD-R (Recordable), rewritable DVD-RAM(Random Access Memory) (or DVD-RW (Rewritable)).

[0004] The DVD video (DVD-ROM) standard supports MPEG-2 for movingpicture compression scheme and not only liner PCM (Pulse CodeModulation) but also AC-3 audio and MPEG audio for audio recordingscheme.

[0005] The DVD video standard further supports sub-picture data obtainedby run-length compressing the bit map data for subtitles and reproducecontrol data (navigation data) for data searching by fast-forwardplayback or fast-rewind playback.

[0006] Furthermore, the DVD video standard supports ISO (InternationalOrganization for Standardization) 9660 and UDF (Universal Disk Format)to allow computers to read data.

[0007] For DVD video (DVD-ROM) optical disks, a 12-cm diametersingle-sided single-layer disk has a storage capacity of about 4.7 GB(Giga Bytes); a 12-cm diameter single-sided double-layer disk has astorage capacity of about 9.5 GB; and a 12-cm diameter double-sideddouble-layer disk has a storage capacity of about 18 GB, provided that650-nm (nanometers) wavelength laser light is used for reading.

[0008] On the other hand, for DVD-RAM (DVD-RW) optical disks, at thepresent time, a 12-cm diameter single-sided disk has a storage capacityof about 2.6 GB and a 12-cm diameter double-sided disk has a storagecapacity of about 5.2 GB. Namely, DVD-RAM optical disks in practical usehave a smaller storage capacity than DVD-ROM disks of the same size.

[0009] In playback-only DVD video (DVD-ROM), like a hierarchical filestructure used by a general-purpose computer operating system, thedirectory structure of information (data files) recorded on aninformation storage medium is such that a subdirectory of video titleset VTS and a subdirectory of audio title set ATS are connected to aroot directory as shown in FIG. 1.

[0010] In the subdirectory of video title set VTS, various video files(including VMGI, VMGM, VTSI, VTSM, and VTS) are so arranged that theindividual files can be managed in order. A specific file (for example,a specific VTS) can be accessed by specifying a path from the rootdirectory to the file.

[0011] Specifically, the root directory of a DVD video disk includes asubdirectory called video title set VTS. The subdirectory can containvarious management data files including VIDEO_TS.IFO orVTS_(—)01_(—)0.IFO, backup files, including VIDEO_TS.BUP andVTS_(—)01_(—)0.BUP, for backing up the information in those managementdata files, and a video data file VTS_(—)01_(—)1.VOB managed on thebasis of the contents of the management data files and used to storedigital video information. The subdirectory can also contain menu datafiles (including VMGM and VTSM) for storing specific menu information.

[0012] A DVD video disk is composed of a video manager VMG and at leastone or up to 99 video title sets VTSs. The video manager VMG is composedof control data VMGI, VMG menu video object set VMGM_VOBS, and backupcontrol data VMGI_BUP. Each data is recorded on an information storagemedium as a single file.

[0013] As shown in FIG. 1, on the DVD video disk, the individual videotitle sets (e.g., video title set VTS #1 and video title set VTS #2)have to be recorded in separate files. In each video title set (e.g.,video title set VTS #1), control data VTSI, VTS menu video object setVTSM_VOBS, and backup control data VTSI_BUP are recorded in separatefiles. Additionally, title video data VTS_(—)01_(—)1.VOB andVTS_(—)01_(—)2.VOB in the VTS are recorded in plural files.

[0014] The DVD-RAM disk uses a UDF file system, not a FAT (FileAllocation Table) file system. The details of UDF will be described indetails later. Like FAT, UDF enables a hierarchical structure of filesand records data in files on an information storage medium. In the priorart, both of the UDF file and the FAT file are filled with data and haveno unrecorded area in them.

[0015] The contents will be explained in detail using one example. Forexample, when a statement has been written using word processor software(such as Ichitaro, Word, or Amipro) running on a PC (Personal Computer),the written statement is recorded on an information storage medium as afile. In this case, all the file is filled with text data. Even if aspace area or a continues enter mark portion with no sentence continueslong in the middle of the written sentence, that portion in the storedfile will be filled with space data and enter data and therefore therewill be no fully unrecorded area in the file.

[0016] Even when the user reads the document file and stores the dataafter deleting the middle of the sentence, an unrecorded area is neverdefined in the stored information and is recorded on the informationstorage medium as a file with the data items before and after thedeleted portion putting together. As a result, the size of the filerecorded on the information storage medium decreases by the amount ofdata in the deleted portion.

[0017] With application software running on an ordinary PC, a file readfrom an information storage medium for editing is transferred as it isto a buffer memory (semiconductor memory) on the PC. The edited data isstored temporarily in the buffer memory on the PC. Once the user hasgiven an instruction to store the file, the edited data stored in thebuffer memory on the PC is written over the whole file on theinformation storage medium. As described above, with the conventionalfile system, such as a FAT or UDF file system, when the file data ischanged, all the data in the file is changed at a time in the overwriteprocess. This is different from the present invention where the data inonly a part of the file is changed.

[0018]FIGS. 2A and 2B illustrate examples of reproducing videoinformation using program chains PGCs on a DVD video disk. As shown inFIG. 2A, the playback data is divided into cells and playback sectionsfrom cell A to cell F are specified. In the individual program chainsPGC #1 to #3, PGC information is defined as shown in FIG. 2B.Specifically, the table in FIG. 2B reads as follows.

[0019] 1. Program chain PGC #1 shows an example of being made up ofcells specifying consecutive playback sections. The playback sequenceis:

[0020] Cell A→Cell B→Cell C.

[0021] 2. Program chain PGC #2 shows an example of being made up ofcells specifying intermittent playback sections. The playback sequenceis:

[0022] Cell D→Cell E→Cell F.

[0023] 3. Program chain PGC #3 shows an example of being made up ofcells specifying disorderly playback sections, regardless of thedirection of playback or repetitive playback. The playback sequence is:

[0024] Cell E→Cell A→Cell D→Cell B→Cell E

[0025] By defining different program chains PGCs as described above,different display sequences can be realized for the same cells. In a DVDvideo disk, all the cell information is not necessarily displayed by asingle program chain PGC because of the freedom of program chain PGCsetting.

[0026] What has been explained above is about the data structure of thevideo information recorded on a playback-only DVD video disk. Aninformation storage medium capable of recording and reproducing videoinformation using a DVD-RAM disk or a DVD-RW disk is now being developedas one form of the DVD family.

[0027] It is desirable that the video information recording format onthe information storage medium capable of video recording andreproducing should have a continuity and a relation with the datastructure of a DVD video disk. In addition, a UDF file system is usedfor DVD-RAM disks or DVD-RW disks, as in the playback-only DVD videodisk.

[0028] When the data structure of the aforementioned DVD video disk isused directly as the data structure on a recordable (videorecordable)information storage medium and the above conventional UDF (or FAT) filesystem is used, the following problems arise:

[0029] 1. Since the control data and video data are recorded in such amanner that they are distributed over plural files, when having deleteda file by mistake, the user is unaware of the position of the erroruntil trying to reproduce the deleted file in the course of playback.For the playback-only DVD video disk, there is no possibility that theuser will delete a file. In the case of recordable/erasable informationstorage mediums, however, there is a danger that the user will delete afile by mistake.

[0030] 2. Since the control data and video data are recorded in such amanner that they are distributed over plural files and the datastructure has the same hierarchical structure as that of the computerdata, it is difficult for the family user unfamiliar with the computerto understand the deleted place or the recorded place. Specifically,knowing only the VTR (Video Tape Recorder) as a medium capable ofrecording video information, the family user wonders which part of thesingle tape the place where the picture has been recorded or deleted hasoccupied. Therefore, showing the user small files of record or theresult of erasing as they are would throw the user into confusion.

[0031] As shown in FIG. 1, in the DVD video disk, information isrecorded in such a manner that it is divided into separate files byvideo title set VTS. Thus, when plural video title sets (VTS#L and VTS#2in FIG. 1) have been recorded on the information storage medium, theuser familiar with only the VTR has no idea about the playbackprocedure.

[0032] 3. With a method of allowing the family user to select a specificcell corresponding to a program chain PGC for the recorded information,some user is liable to fall into confusion. Specifically, knowing onlythe VTR as a medium capable of recording video information, the familyuser will probably wonder which part of the single tape the place wherethe picture has been recorded or deleted has occupied. Therefore, itwould be difficult for the user to understand the concept of selectingcells by a program chain PGC on a playback-only DVD video disk.

[0033] 4. In a data file recorded using the conventional UDF or FAT,there is no unrecorded area. Therefore, when part of a specific dataitem in a file has been deleted or a few pieces of video informationhave been added, the data items in front of and behind the deletedportion are squeezed together and connected or the pieces of informationare added to the end of the existing data. Each time data is deleted oradded, the size of the whole data file has to be changed and all thechanged data file has to be recorded on the information storage mediumagain. As a result, it take a very long time to complete the editingprocess.

[0034] Specifically, with the conventional UDF or FAT, since a file hasno unrecorded area, the following processes cannot be carried out:

[0035] (a) The process of changing the erased place to an unrecordedarea when part of the data in a file has been deleted.

[0036] (b) The process of recording additional data on an unrecordedarea in a file without changing the entire file size.

[0037] Therefore, each time the data is deleted partially or added, thefile size has to be changed.

[0038] As a result, the entire file has to be recorded again on theinformation storage medium. In the case of a video file in which videoinformation has been recorded, the size of a single video file is aslarge as more than several hundreds of megabytes (MB). If a file aslarge as several hundreds of megabytes is all recorded again on theinformation storage medium each time a slight change has been made, itwill take an extremely long time to change the contents of the file.

[0039] For a further description of the prior art, reference may be madeto:

[0040] Japanese Patent Application No. 040876 (filed on Feb. 23, 1998)Japanese Patent Application No. 040877 (filed on Feb. 23, 1998) JapanesePatent Application No. 040879 (filed on Feb. 23, 1998).

BRIEF SUMMARY OF THE INVENTION

[0041] It is, accordingly, a first object of the present invention toovercome the disadvantages in the prior art by providing an informationrecording method for creating a data structure that causes a place whereinformation is recorded or deleted on an information storage medium tocorrespond spuriously to a place on a single tape, such as a VTR tape,in order to provide the family user familiar with only the VTR as amedium capable of recording video information with an easy-touseinterface, and by providing an information reproducing method ofreproducing the recorded information.

[0042] A second object of the present invention is to provide aninformation recording method for creating a data structure that enablesthe general user to find the mistake readily even when having deleted afile by mistake and an information method of reproducing the informationcreated using the data structure.

[0043] To achieve the foregoing objects, at least one of a video filecontaining video information, a still picture file containing stillpicture information, and an audio file containing audio information isrecorded on an information storage medium (e.g., an optical disk) in theinvention. Specifically, at least one of a video file, a still picturefile, and an audio file is recorded on an information storage medium onwhich information is recorded in files and from which the informationrecorded in a file can be read in a playback operation.

[0044] Furthermore, in the invention, a management file havingmanagement information on a control method of reproducing all theinformation recorded in at least one of a video file, a still picturefile, and an audio file is recorded on an information storage medium(e.g., an optical disk). Specifically, a management file having not onlya series of links to reproduce all the information in the recording filebut also playback sequence information indicating the sequence forreproducing all the information recorded in the file is recorded on aninformation storage medium on which information is recorded in files andfrom which the information in a file can be read in a playback operationand on which at least one of a video file, a still picture file, and anaudio file has been recorded.

[0045] Additional objects and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0046] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate presently preferredembodiments of the invention, and together with the general descriptiongiven above and the detailed description of the preferred embodimentsgiven below, serve to explain the principles of the invention.

[0047]FIG. 1 is a diagram to help explain the structure of aconventional directory for information (data files) recorded on anoptical disk;

[0048]FIGS. 2A and 2B are diagrams to help explain the conventionalrelationship between cells and PGC information;

[0049]FIGS. 3A to 3H are related to an embodiment of the presentinvention and illustrate a hierarchical structure of informationrecorded on an optical disk;

[0050]FIG. 4 is a diagram to help explain a directory structure ofinformation (data files) recorded on an optical disk;

[0051]FIG. 5 is a diagram to help explain another directory structure ofinformation (data files) recorded on an optical disk;

[0052]FIG. 6 is a diagram to help explain still another directorystructure of information (data files) recorded on an optical disk;

[0053]FIG. 7 is a diagram to help explain the relationship between videoobjects and cells;

[0054]FIG. 8 is a diagram to help explain a data structure of cell timecontrol general information and cell time search information;

[0055]FIG. 9 is a diagram to help explain another data structure of celltime control general information and cell time search information;

[0056]FIGS. 10A and 10B are diagrams to help explain the relationshipbetween cells and PGC information;

[0057]FIG. 11 is a block diagram of an information recording/reproducingapparatus for optical disks;

[0058]FIGS. 12A and 12B are diagrams to help explain an example of afile system constructed using a UDF;

[0059]FIGS. 13A and 13B are diagrams to help explain an example of afile system constructed using a UDF, by reference to FIGS. 12A and 12B;

[0060]FIG. 14 is a diagram to help explain the basic relationshipbetween the hierarchical file system of FIG. 4 and the contents of theinformation recorded on the optical disk;

[0061]FIG. 15 is a diagram of a part of the file ID descriptor fordescribing information on files (including root directory,subdirectories, and file data) in the file structure having thehierarchical structure of FIG. 4;

[0062]FIG. 16 is a diagram of a part of the contents of the file entrydescribing the recorded position of the specified file in the filestructure having the hierarchical structure of FIG. 4;

[0063]FIG. 17 is a diagram to help explain the contents of a shortallocation descriptor describing the recorded position of a consecutivesector set (extent) on an optical disk;

[0064]FIGS. 18A to 18D are diagrams to help explain a conventionalmethod of setting file recording positions using a UDF;

[0065]FIGS. 19A to 19D are diagrams to help explain a method of settingfile recording positions using a UDF related to the present invention;

[0066]FIG. 20 is a diagram to help explain a data structure of the celltime general information and cell VOBU table shown in FIG. 3H;

[0067]FIGS. 21A to 21D are diagrams to help explain the details of thedata in the video file shown in FIG. 4;

[0068]FIG. 22 is a diagram to help explain the details of the data inthe VOB control information shown in FIG. 3F;

[0069]FIGS. 23A to 23H are diagrams to help explain another example of ahierarchical structure of information recorded on an optical disk;

[0070]FIG. 24 is a diagram to help explain an example of a directorystructure of information (data files) recorded on an optical disk usingthe data structure shown in FIGS. 23A to 23H;

[0071]FIG. 25 is a conceptual diagram to help explain a case where acell playback sequence by the original PGC is changed by a user definedPGC;

[0072]FIG. 26 is a diagram to help explain a case where the original PGCis composed of plural programs;

[0073]FIG. 27 is a diagram to help explain the PGC information includedin the navigation data in FIG. 23D;

[0074]FIG. 28 is a diagram to help explain the details of the PGCgeneral information in the PGC information;

[0075]FIG. 29 is a diagram to help explain the details of the programinformation in the PGC information;

[0076]FIG. 30 is a diagram to help explain the details of the programtype in the program information;

[0077]FIG. 31 is a diagram to help explain the details of the thumbnailpointer information in the program information;

[0078]FIG. 32 is a diagram to help explain a still picture VOB groupS_VOG for thumbnail points in the thumbnail pointer information;

[0079]FIG. 33 is a diagram to help explain the details of the cellinformation search pointer in the PGC information;

[0080]FIG. 34 is a diagram to help explain the details of the cellinformation in the PGC information;

[0081]FIG. 35 is a diagram to help explain the details of the movie cellinformation in the cell information;

[0082]FIG. 36 is a diagram to help explain the details of the movie cellgeneral information constituting the movie cell information; and

[0083]FIG. 37 is a diagram to help explain the details of the cell typein the movie cell general information.

DETAILED DESCRIPTION OF THE INVENTION

[0084] Hereinafter, an embodiment of the present invention will beexplained by reference to the accompanying drawings. Using FIGS. 3A to3H, the data structure of video information recorded on an informationstorage medium by an information recording method of the presentinvention will be explained. FIG. 3A is a perspective view of an opticaldisk 1001 serving as an information storage medium.

[0085]FIG. 3B shows a rough data structure of information recorded onthe optical disk 1001. In FIG. 3B, a lead-in area 1002, volume & filemanager information 1003, a data area 1004, and a lead-out area 1005 arearranged in that order from the inner circumference side 1006 to outercircumference side 1007 of the optical disk 1001.

[0086] The lead-in area 1002 has an embossed data zone where the lightreflecting surface is uneven, a mirror zone where the surface is flat(mirrorlike), and a rewritable data zone where information can berewritten.

[0087] In the volume & file manager information 1003, information on allof the audio & video data files or volumes is recorded in a rewritabledata zone where the user can record or rewrite data.

[0088] The data area 1004 has a rewritable data zone where the user canrecord or rewrite data. The lead-out area 1005 is made up of arewritable data zone where information can be rewritten.

[0089] In the embossed data zone of the lead-in area 1002, the followingpieces of information have been recorded beforehand: information on thedisk type, such as DVD-ROM/-RAM/-R, the disk size, and the recordingdensity, information on all of the information storage medium, includingphysical sector numbers indicating the recording start/recording endpositions, information on recording, reproducing, and erasingcharacteristics, including the recording power, recording pulse width,erasing power, reproducing power, and linear velocity in recording orerasing, and information on the manufacture of individual informationstorage mediums, including serial numbers.

[0090] Each of the rewritable zone in the lead-in area 1002 and that inthe lead-out area 1005 has a disk name recording area for eachinformation storage medium, a trial recording area (for checking therecording and erasing conditions), and a management informationrecording area for defective areas in the data area 1004. An informationrecording and reproducing apparatus can record information on each ofthose areas.

[0091] In the data area 1004 sandwiched between the lead-in area 1002and the lead-out area 1005, computer data and audio & video data can berecorded in such a manner that they are intermingled as shown in FIG.3C. The order in which computer data and audio & video data are recordedand the recording information size of them are arbitrary. The areas inwhich computer data is recorded are called computer data areas 1008,1010. The area in which audio & video data is recorded is called anaudio & video data area 1009.

[0092] As shown in FIG. 3D, the data structure of information recordedin the audio & video data area 1009 includes control information 1011necessary to perform each of video recording (audio recording),reproducing, editing, and retrieving processes, a video object 1012 ofvideo information on the contents of the video data, a picture object1013 of information on thumbnails for retrieving the desired one of thestill pictures, including slides, or the desired part of the video dataor on thumbnails for editing, and an audio object 1014 of information onthe recording of the contents of audio data.

[0093] As shown in FIG. 3E, the contents of the control information 1011include AV data control information 1101 that controls the datastructure of the video object 1012 and is management information aboutinformation on the recording position on an optical disk 1001 serving asan information storage medium, playback control information 1021 servingas control information necessary in playback, recording controlinformation 1022 serving as control information necessary in recording(video recording and audio recording), edit control information 1023serving as control information necessary in editing, and thumbnailpicture control information 1024 serving as management information onthumbnails (thumbnail pictures) for retrieving the desired portion ofthe video data or for editing.

[0094] As shown in FIG. 3F, the data structure of the AV data controlinformation 1101 includes PGC control information 1103 serving asinformation on video information playback programs (sequence) and celltime control information 1104 serving as information on the datastructure used as an audio information basic unit.

[0095] What has been described above is a general view of FIGS. 3A to3F. Some supplementary explanation will be given about each piece ofinformation. In the volume & file manager information 1003, informationon all the volume and information on the number of files of contained PCdata, the number of files' of AV data, and recording layer informationare recorded.

[0096] The following are recorded as the recording layer information:the number of component layers (e.g., a single RAM/ROM two-layer disk iscounted as two layers, a single ROM two-layer disk is counted as twolayers, and an n number of single-sided disks are counted as n layers),a logical sector number range table allocated to each layer (a capacityfor each layer), characteristics for each layer (e.g., a DVD-RAM disk,the RAM section of a RAM/ROM two-layer disk, a CD-ROM, and a CD-R), alogical sector number range table allocated in zones in the RAM area foreach layer (including information on the capacity of the rewritable areafor each layer), and ID (Identifier) information unique to each layer(to find disk replacement in the multiple-disk pack). The recordinglayer information makes it possible to set consecutive logical sectornumbers to a multiple-disk pack or a RAM/ROM two-layer disk to create asingle large volume space.

[0097] Furthermore, the following are recorded in the playback controlinformation 1021: information on a playback sequence for the integrationof program chains PGCs, the original PGC information (corresponding to2213 in FIG. 23E or the original PGC in FIG. 25) or the information (thesequence for reproducing all the recorded cells consecutively)indicating spurious recording positions when an information storagemedium is regarded as a single tape, such as a VTR or a DVC (DigitalVideo Cassette), information on simultaneous playback of plural screenswith different pieces of video information, and retrieval information(that causes the corresponding ID and the start time table in the cellto be recorded for each retrieval category and enables the user toselect a category and access the video information directly).

[0098] Moreover, in the recording control information 1022, programreserved recording information is recorded. In addition, the followingare recorded in the edit control information 1023: special editinformation in program chains PGCs (where the relevant time setinformation and special edit content are written as EDL information),and file conversion information (the information to convert a specificpart of an AV file into a file capable of special editing on a PC, suchas an AVI (Audio Video Interleaving) file and specify a place to storethe converted file.

[0099]FIG. 4 shows a directory structure having only one video file on asingle information storage medium of the present invention. Therecording/reproducing video data itself in the video object 1012 of FIG.3D is recorded in the only video file RWVIDEO_OBJECT.VOB of FIG. 4.

[0100] The recording/reproducing video management data in the controlinformation 1011 of FIG. 3D is recorded in a file RWVIDEO_CONTROL.IFOand its backup file RWVIDEO_CONTROL.BUP shown in FIG. 4.

[0101] The RWVIDEO_CONTROL.BUP is updated each time the contents ofRWVIDEO_CONTROL.IFO is updated. In the reproducing, additionalrecording, partial deleting, or editing of ordinary video information,the RWVIDEO_CONTROL.IFO is used as recording/reproducing videomanagement data. Recordable information storage mediums, such asDVD-RAMs, are more liable to be affected by dust or a flaw on or in thesurface of the information storage medium in a playback operation thanin a recording operation. Therefore, when there is dust or a flaw on orin the surface, even if the information in the RWVIDEO_CONTROL.IFO hasbeen read accurately, the dust or flaw might sensitively affect therewriting (or recording) of the information in the RWVIDEO_CONTROL.IFO,making it impossible to update the contents. To overcome this problem,not only the RWVIDEO_CONTROL.IFO containing the management data but alsoRWVIDEO_CONTROL.BUP containing the same contents as those of theRWVIDEO_CONTROL.IFO are recorded on a recordable information storagemedium. This increases the reliability of the recording/reproducingvideo management data.

[0102] The information in the picture object 1013 of FIG. 3D is dividedinto still picture data and thumbnail picture data, which are recordedin a file RWPICTURE_OBJECT.POB and a file RWTHUMNAIL_OBJECT.POB shown inFIG. 4. The audio object 1014 of FIG. 3D is recorded in a fileRWAUDIO_OBJECT.AOB shown in FIG. 4.

[0103] The individual files related to a DVD video disk as shown in FIG.1 are recorded under a subdirectory of video title set VIDEO_TS shown inFIG. 4, although not shown in the figure. According to the informationin RWVIDEO_CONTROL.IFO (recording/reproducing video management data),they are linked with RWVIDEO_OBJECT.VOB (recording/reproducing videodata) to enable seamless, continuous playback of them.

[0104]FIG. 5 shows another example of the present invention.Specifically, video data, still picture data, thumbnail data, and audiodata are all recorded in a single file RWOBJECT.OB. Although all thedata for recording and reproducing is recorded in a file, theRWVIDEO_CONTROL.IFO (recording/reproducing video management data) inwhich the management information including the playback procedure isrecorded is recorded in a separate file.

[0105]FIG. 6 shows another embodiment of the present invention. Unlikethe embodiment of FIG. 5, the embodiment of FIG. 6 is such that thevideo recording/reproducing data including management data is allrecorded in a single file RWAVFILE.DAT (Rewritable Audio Video File). Inthis case, the file RWAVFILE.DAT is placed not under a specificsubdirectory but just under the root directory.

[0106] Next, using FIG. 7, the relationship between video objects VOBsand cells will be explained. As shown in FIG. 7, each cell 84 is made upof more than one video object unit VOBU 85. Each video object unit VOBU85 is a collection (a pack train) of a VOBU begin pack 86, video packs(V packs) 88, sub-picture packs (SP packs) 90, and an audio pack (Apack) 91 in that order, with the VOBU begin pack 86 at the head.

[0107] In the VOBU begin pack 86, the time that the video object unitVOBU 85 was recorded on the information storage medium has been recordedin the form of year, month, day of the month, hours, minutes, andseconds. With the recorded time written in the VOBU begin pack 86, whenthe video object unit VOBU 85 is reproduced, the recorded timereproduced is compared with the date and time that the relevant celltime of FIG. 20 was created or last updated. This makes it possible tocheck in real time whether the video object unit VOBU 85 currently beingreproduced coincides with the video object unit VOBU 85 specified in thecell time general information #m 1116.

[0108] As described above, the reliability of the data in playback canbe increased by placing the VOBU begin pack 86 at the beginning of thevideo object unit VOBU 85 and recording the recorded time in the VOBUbegin pack 86. Moreover, in the VOBU begin pack 86, information relatedto the video object unit VOBU 85 automatically created in themicrocomputer block 30 of the information recording/reproducingapparatus of FIG. 11 can be recorded. Information used by theinformation recording/reproducing apparatus is recorded as theinformation related to the video object unit 85, which helps not onlyincrease the reliability of the reproduced video object unit VOBU 85 butalso improve the performance of the apparatus, such as the shortening ofthe access time. Furthermore, the video data program (EPG) and profileinformation on the video characters can be recorded as the informationrelated to the video object unit VOBU 85, which helps improve service tothe user during video data playback.

[0109] Specifically, the video object unit VOBU 85 is defined as acollection of all the packs starting from a VOBU begin pack (navigationpack) 86 to the one just before the next VOBU begin pack (navigationpack) 86. Those packs are used as the smallest units in transferringdata. The smallest unit in logical processing is a cell. Logicalprocessing is done in cells.

[0110] The playback time of the video object unit VOBU 85 corresponds tothe playback time of the video data made up of more than one video groupGOP (Group of Picture) contained in the video object unit VOBU 85. Theplayback time is set to the range from 0.4 second to 1.2 seconds. In theMPEG standard, the playback time of one GOP is normally about 0.5second. One GOP contains screen data compressed so that about 15pictures may be reproduced in about 0.5 second.

[0111] When a video object unit VOBU 85 includes video data, GOPs(complying with the MPEG standard) composed of video packs 88,sub-picture packs 90, and audio packs 91 are arranged to produce a videodata stream. The video object unit VOBU 85 is determined on the basis ofthe playback time of the GOPs, regardless of the number of GOPs. At thehead of the video object unit VOBU 85, a VOBU begin pack 86 is alwaysplaced as shown in FIG. 7.

[0112] Even when the playback data contains only audio and/orsub-picture data, it is constructed using a video object unit VOBU 85 asone unit. For example, when a video object unit VOBU 85 is made up ofonly an audio pack 91, with a VOBU begin pack 86 at the head, the audiopack 91 to be reproduced within the playback time of the video objectunit VOBU 85 to which the audio data belongs is stored in the videoobject unit VOBU 85, as in the video object VOB 83 of video data.

[0113] In an information recording and reproducing apparatus capable ofrecording on an information storage medium a video title set VTSincluding a video object set VOBS 82 of the structure as shown in FIG.7, the user often wants to edit the contents of the recording afterhaving recorded the video title set VTS. To meet the desire, dummy packs89 are allowed to be inserted in each video object unit VOBU 85. Thedummy pack 89 can be used later to record editing data.

[0114] As shown in FIG. 7, a video object set VTSTT_VOBS 82 is a set ofmore than one video object VOB 83. The video objects VOBs 83 in a videoobject set VOBS 82 are used for the same application.

[0115] A video object set VOBS 82 for menus is normally made up of onevideo object VOB 83, in which plural menu screen display data items arestored. In contrast, a video object set VOBS 82 for title sets isnormally made up of plural video objects VOBs 83.

[0116] When a concert video for a certain rock band is taken as anexample, video objects VOBs 83 constituting a video object setVTSTT_VOBS 82 for title sets can be considered as corresponding to thevideo data for the performance of the band. In this case, by specifyingthe video objects VOBs 83, for example, the third piece on the band'sconcert program can be reproduced.

[0117] In the video objects VOBs 83 constituting a video object setVTSM_VOBS for menus, the menu data for all the pieces of the band'sconcert program is stored. According to the menu on the screen, aspecific piece of music, for example, an encore, can be reproduced.

[0118] In an ordinary video program, one video object set VOBS 82 can becomposed of one video object VOB 83. In this case, one video stream iscompleted with a single video object VOB 83.

[0119] On the other hand, for example, in the case of a collection ofanimations with multiple stories or omnibus movies, plural video streams(plural program chains PGCs) can be provided for each story in one videoobject set VOBS 82. In this case, each video stream is stored in thecorresponding video object VOB 83. At that time, the audio stream andsub-picture stream related to each video stream are also completed ineach video object VOB 83.

[0120] Each video object VOB 83 is assigned an identification number IDN#j (j=1 to j). By the identification number, the video object VOB 83 canbe identified. A video object VOB 83 is composed of one or more cells84. An ordinary video stream is made up of plural cells. A video streamfor menus may be composed of one cell 84. Like the video object VOB 83,each cell 84 is assigned an identification number IDN #j (i=1 to j).

[0121] The cell time control information 1104 of FIG. 3F is composed ofcell time control general information 1111, cell time search information1112, and one or more pieces of cell time information 1113 to 1115 asshown in FIG. 3G.

[0122] Of these, the pieces of cell time information 1113 to 1115 eachhave cell time general information 1116 and a cell VOBU table 1117 asshown in FIG. 3H. The data structure of the cell time control generalinformation 1111 and that of the cell time search information 1112 areshown in FIGS. 8 and 9, the details of which will be explained later.

[0123] The playback sequence of the program chain (PGC) controlinformation 1103 of FIG. 3F is determined by a program chains PGC andcells. The program chain PGC is a unit to execute a series of playbackspecifying the order in which cells are reproduced. A cell is a playbacksection specifying playback data by a start address and an end address.

[0124] The program chain (PGC) control information 1103 is composed ofPGC information management information, one or more pieces ofsearch-pointer-of-PGC information, and PGC information.

[0125] The PGC information management information includes information(number-of-PGCs information) on the number of program chains PGCs. Thesearch-pointer-of-PGC information points at the head of each PGCinformation and makes it easy to search.

[0126] The PGC information includes PGC general information and one ormore pieces of search-pointer-of-cell-time information. The PGC generalinformation includes the playback time of program chains PGCs andinformation on the number of cells (search-pointer-of-cell-timeinformation). In the search-pointer-of-cell-time information, thepositions of the pieces of cell time information 1113 to 1115 arewritten.

[0127] An example of reproducing video information using a program chainPGC in a conventional DVD video has been explained in FIGS. 2A and 2B.In the conventional example, all the video information (all the cells)is not necessarily reproduced continuously using a single program chainPGC. Since video information has been recorded in DVD video, thereproducing method of FIGS. 2A and 2B will not give the user a sense ofincongruity.

[0128] In a video file of the present invention in which the user canrecord pictures, the user records video information. With thereproducing method as explained in FIGS. 2A and 2B, the user familiarwith the VTR is liable to fall into confusion about the relationshipbetween the total video recording time and the remaining time.

[0129] On the other hand, with the present invention, the playbacksequence is determined in a single program chain PGC so that all thevideo information in a video file may be reproduced continuously asshown in FIGS. 10A and 10B. As shown in FIG. 10A, on an informationstorage medium, video objects VOBs are arranged from the innercircumference side of the disk in this order:

[0130] VOB_IDN #1→VOB_IDN #3→VOB_IDN #2.

[0131] According to this arrangement, cells are arranged from the innercircumference side of the disk in this order:

[0132] cell A→cell B→cell C→cell F→cell G→cell D→cell E.

[0133] In contrast, a program chain PGC indicating the sequence in whichall the cells shown in FIG. 10B are reproduced consecutively reproducescells in this order:

[0134] cell A→cell B→cell C→cell D→cell E→cell F→cell G.

[0135]FIG. 11 shows the configuration of an informationrecording/reproducing apparatus which records and reproduce informationon and from an information storage medium having video files shown inFIG. 1 or 4. The information recording/reproducing apparatus comprisesthe following main component parts: an information recording/reproducingsection 32 that rotates an optical disk 1001 acting as an informationstorage medium having video files and reads and writes information fromand onto the optical disk 1001, an encoder section 50 constituting thevideo recording side, a decoder section 60 constituting the reproducingside, and a microcomputer block 30 that controls the operation of themain part of the apparatus.

[0136] The encoder section 50 includes an ADC (Analog Digital Converter)52, a V (Video) encoder 53, an A (Audio) encoder 54, an SP (Sub-picture)encoder 55, a formatter 56, and a buffer memory 57.

[0137] The ADC 52 receives an external analog video signal + an externalanalog audio signal from an AV input section 42 or an analog TV signal +an analog audio signal from a TV (Television) tuner 44. The ADC 52converts the inputted analog video signal into a digital signal at, forexample, a sampling frequency of 13.5 MHz, with the number ofquantization bits being eight. Specifically, luminance component Y,color difference component Cr (or Y-R), and color difference componentCb (or Y-B) are each quantized in eight bits.

[0138] Similarly, the ADC 52 converts the inputted analog audio signalinto a digital signal at, for example, a sampling frequency of 48 KHz,with the number of quantization bits being 16.

[0139] When the analog video signal and digital audio signal areinputted to the ADC 52, the ADC 52 allows the digital audio signal topass through. The ADC 52 may reduce only jitters incidental to thedigital audio signal or change the sampling rate or the number ofquantization bits without changing the contents of the digital audiosignal.

[0140] On the other hand, when the digital video signal and digitalaudio signal are inputted to the ADC 52, the ADC 52 allows the digitalvideo signal and digital audio signal to pass through. In this case,too, the ADC 52 may reduce jitters or change the sampling rate withoutchanging the contents of the digital video signal and digital audiosignal.

[0141] The digital video signal outputted from the ADC 52 is sent to theformatter 56 via the V encoder 53. The digital audio signal outputtedfrom the ADC 52 is sent to the formatter 56 via the A encoder 54.

[0142] The V encoder 53 has the function of converting the inputteddigital video signal into a digital signal compressed at a variable bitrate according to the MPEG-2 or MPEG-1 standard.

[0143] The A encoder 54 has the function of converting the inputteddigital audio signal into a digital signal compressed at a fixed bitrate or a linear PCM digital signal according to the MPEG or AC-3standard.

[0144] When the sub-picture information is inputted from the AV inputsection 42 (e.g., the signal from a DVD video player with an independentoutput terminal for sub-picture signal), or when a DVD video signal withsuch a data structure is broadcast and then received by the TV tuner 44,the sub-picture signal (sup-picture pack) in the DVD video signal isinputted to the SP encoder 55. The sup-picture signal inputted to the SPencoder 55 is arranged into a specific signal form, which is sent to theformatter 56.

[0145] The formatter 56 subjects the inputted video signal, audiosignal, and sup-picture signal to specific processes using the buffermemory 57 as a work area and outputs the recording data conforming tothe format (file structure) explained in FIG. 7 to a data processor 36.

[0146] Here, a standard encode process for creating the recording datawill be explained briefly. In the encoder section 50 of FIG. 11, whenthe encode process is started, the parameters necessary to encode thevideo (main picture) data and audio data are set.

[0147] Next, by pre-encoding the main picture data using the setparameters, the distribution of the amount of codes best suitable forthe set average transfer rate (recording rate) is calculated. In thisway, the encoding process of the main picture data is executed on thebasis of the amount-of-codes distribution calculated in the pre-encodingprocess. At that time, the encoding process of the audio data isexecuted at the same time.

[0148] When the amount of data compression is insufficient as a resultof the pre-encoding process (or when the desired video program does notfit in an information storage medium), if the pre-encoding process canbe executed again (e.g., the video recording source is a repeatedlyreproducible source, such as video tape or a video disk), part of themain picture data is encoded again and the re-encoded part of the mainpicture data is replaced with the main picture data portion previouslypre-encoded. By such a series of processes, the main picture data andaudio data are encoded, thereby reducing remarkably the value of theaverage bit rate necessary for recording.

[0149] Similarly, the parameters necessary to encode the sup-picturedata are set and the encoded sup-picture data is produced.

[0150] The encoded main picture data, audio data, and sup-picture dataare combined and formatted into the structure of the video title setVTS.

[0151] Specifically, a cell is set as the smallest unit of the mainpicture data (video data). Then, the cell time information as shown inFIGS. 8 and 9 is created as described later. Next, the structure ofcells constituting a program chain PGC as shown in FIGS. 10A and 10B andthe attributes of the main picture, sub-picture, and audio are set,thereby creating a recording/reproducing video management data fileRWVIDEO_CONTROL.IFO including various pieces of information.

[0152] The encoded main picture data, audio data, and sup-picture dataare divided into packs of a constant size (2048 bytes) as shown in FIG.7. Dummy packs 89 are inserted in the packs whenever necessary. In thepacks other than the dummy packs 89, time stamps, including PTS(Presentation Time Stamp) and DTS (Decoding Time Stamp), are writtenwhenever necessary. For the PTS of a sub-picture, the time delayed anarbitrary time from the PTS of the main picture data or audio data inthe same playback time zone can be written.

[0153] Then, a VOBU begin pack (navigation pack) 86 is placed at thehead, followed by cells, in a video object unit VOBU 85 unit, whichthereby creates a video object VOB 83 composed of plural cells. One ormore of the video object VOB 83 are gathered together to form a videoobject set VOBS 82, which is recorded in the recording/reproducing videodata file RWVIDEO_OBJECT.VOB of FIG. 4.

[0154] When the DVD playback signal is digital copied from a DVD videoplayer, the contents of the cells, program chains, management tables,and time stamps need not be created again, because they have beendetermined already. However, to construct a DVD video recorder so thatit enables a digital copy of the DVD playback signal, electronicwatermarks or other copyright protecting means have to be provided.

[0155] A disk drive section that reads and writes (video records and/orreproduces) information from and onto an information storage medium (oroptical disk 1001) includes a disk changer section 100, an informationrecording/reproducing section 32, a temporary storage section 34, a dataprocessor 36, and an STC (System Time Counter or System Time Clock) 38.

[0156] The temporary storage section 34 is used to buffer a constantamount of the data (the data outputted from the encoder section 50)written onto an information storage medium (optical disk 1001) via theinformation recording/reproducing section 32 or to buffer a constantamount of the data (the data inputted to the decoder section 60)reproduced from the information storage medium (optical disk 1001) viathe information recording/reproducing section 32.

[0157] For example, when the temporary storage section 34 is composed ofa 4-Mbyte semiconductor memory (D-RAM (dynamic RAM)), about eightseconds of recording or playback data can be buffered at a recordingrate of an average of 4 Mbps (bit per second). When the temporarystorage section 34 is composed of a 16-Mbyte EEP (Electrically Erasableand Programmable) ROM (flash memory), about 30 seconds of recording orplayback data can be buffered at a recording rate of an average of 4Mbps. Furthermore, when the temporary storage section 34 is composed ofa 100-Mbyte ultra-compact HDD (hard Disk Drive), about three minutes ormore of recording or playback data can be buffered at a recording rateof an average of 4 Mbps.

[0158] When the information storage medium (optical disk 1001) is usedup in the course of video recording, the temporary storage section 34may store temporarily the video information until the informationstorage medium (optical disk 1001) has been replaced with a new one.

[0159] Furthermore, when a high-speed drive (a double-speed drive orfaster drive) is used as the information recording/reproducing section32, the temporary storage section 34 can be used to store temporarilythe data read beyond the capacity of the ordinary drive within aspecific time. Once the data read during playback has buffered in thetemporary storage section 34, even when the optical head (not shown) hasmade an error in reading due to vibrational shocks, use of thereproduced data buffered in the temporary storage section 34 preventsthe reproduced pictures from being interrupted.

[0160] Although not shown in FIG. 11, making an external card slot inthe information recording/reproducing apparatus would enable the EEPROMto be sold separately as an optional IC (Integrated Circuit) card.Moreover, providing the information recording/reproducing apparatus withan external drive slot or a SCSI (Small Computer System Interface) wouldenable the HDD to be sold separately as an optional extension drive.

[0161] Under the control of the microcomputer block 30, the dataprocessor 36 of FIG. 11 supplies the DVD recording data outputted fromthe encoder section 50 to the information recording/reproducing section32, receives the DVD playback signal reproduced from the informationstorage medium (optical disk 1001) from the informationrecording/reproducing section 32, rewrites the management informationrecorded on the information storage medium, or deletes the data (filesor video title sets VTSs) recorded on the information storage medium.

[0162] The microprocessor block 30 includes an MPU (Micro ProcessingUnit) (or a CPU (Central Processing Unit)), a ROM in which controlprograms have been written, and a RAM for providing the necessary workarea to execute programs.

[0163] The MPU of the microcomputer block 30 uses the RAM as a work areaaccording to the control programs stored in the ROM and effects faultyplace sensing, unrecorded area sensing, video recording informationrecording position setting, UDF recording, AV address setting, andothers.

[0164] Of the results of execution by the MPU, the contents that shouldbe reported to the user of the information recording/reproducingapparatus are displayed on either the display section 48 of the DVDvideo recorder or on the screen of a monitor display (OSD).

[0165] The timing for the microcomputer block 30 to control a diskchanger section 100, the information recording/reproducing section 32,the data processor 36, and the encoder section 50 and/or decoder section60 may be based on the time data from the STC 38. The recording andreproducing operations are generally executed in synchronization withthe time clock from the STC 38. The other processes may be executed withthe timing independent of the STC 38.

[0166] The decoder section 60 includes the following: a separator 62that separates each pack from the video information having the packstructure of FIG. 7, a memory 63 used in executing the pack separationand other signal processes, a V decoder 64 that decodes the main picturedata (the contents of the video packs 88 in FIG. 7) separated by theseparator 62, an SP decoder 65 that decodes the sup-picture data (thecontents of the sup-picture packs in FIG. 7) separated by the separator62, an A decoder 68 that decodes the audio data (the contents of theaudio packs 91 in FIG. 7) separated by the separator 62, a videoprocessor 66 that combines the main picture data from the V decoder 64with the sub-picture data from the SP decoder 65 to superimposesub-pictures including menus, highlight buttons, and subtitles on themain picture, a V-DAC 67 that converts the digital video output from thevideo processor 66 into an analog video signal, and an A-DAC 69 thatconverts the digital audio output from the A decoder 68 into an analogaudio signal.

[0167] The analog video signal from the V-DAC 67 and the analog audiosignal from the A-DAC 69 are supplied to an external component (amulti-channel stereo unit (e.g., a 2-channel to 6-channel stereo unit)+amonitor TV or a projector) (not shown).

[0168] The OSD display data from the microcomputer block 30 is inputtedto the separator 62 of the decoder section 60 and passes through the Vdecoder 64 (which does not decode it). The OSD display data is theninputted to the video processor 66. Then, the OSD display data issuperimposed on the main picture. The resulting picture is supplied toan external monitor TV connected to the AV output section 46. Thisenables a warning message to be displayed together with the mainpicture.

[0169] When a DVD-RAM disk is used as an information storage medium forrecording video files, the UDF is often used as a file format.Therefore, the contents of the UDF will be described by reference toFIGS. 12A to 17.

[0170] (A) Rough Explanation of UDF

[0171] (A-1) What is UDF?

[0172] UDF is an abbreviation of universal disk format. It shows therule for a file management method mainly in a disk-like informationstorage medium. The CD-ROM, CD-R, CD-RW, DVD video, DVD-ROM, DVD-R, andDVD-RAM employ the UDF format standardized by ISO 9660.

[0173] The file management system is based on the assumption that ahierarchical file system which basically has a root directory as aparent and manages files in a tree-like manner. The UDF format chieflycomplying with the DVD-RAM standard (File System Specifications) will beexplained. Most part of the explanation below applies to the DVD-ROMstandard.

[0174] (A-2) Summary of UDF

[0175] (A-2-1) The Contents of File Information Recorded on anInformation Storage Medium

[0176] A collection of information is called file data. When informationis recorded on an information storage medium, recording is done in unitsof file data. To distinguish one collection of file data from another,each collection of file data is assigned a unique file name. Groupingplural collections of file data having the common contents ofinformation facilitates file management and file retrieval. A group ofcollections of file data is called a directory or a folder. Eachdirectory is assigned a unique directory name (or folder name).

[0177] Furthermore, plural directories (or folders) can be put togetherinto a higher-order directory (or higher-order folder) as a group at thepreceding level of hierarchy. Here, the file data and the directory(folder) are generically called files.

[0178] When information is recorded, the following pieces of informationare recorded on an information storage medium:

[0179] The contents of collections of file data

[0180] File name corresponding to each collection of file data

[0181] Storage place of each collection of file data (Under whichdirectory each collection of file data is recorded).

[0182] In addition, the following pieces of information on eachdirectory (or folder) are recorded on the information storage medium:

[0183] Directory name (of folder name)

[0184] Position to which each directory (or folder) belongs (position ofthe higher-order directory (or higher-order folder) serving as theirparent).

[0185] (A-2-2) Information Recording Format on an Information StorageMedium

[0186] All the recording area on the information storage medium isdivided into logical sectors using 2048 bytes as the smallest unit. Allthe logical sectors are assigned logical sector serial numbers. Wheninformation is recorded on the information storage medium, informationis recorded in logical sectors. The recording places on the informationstorage medium are managed by the logical sector numbers of the logicalsectors in which the information has been recorded.

[0187] As shown in FIGS. 12A, 12B, 13A and 13B, the logical sectors inwhich information on the file structure 486 and file data 487 have beenrecorded are called logical blocks. The logical blocks are assignedlogical block numbers' (LBNS) in connection with the logical sectornumbers (LSNs). The length of the logical block is set to 2048 bytes asthat of the logical sector is.

[0188] (A-2-3) An Example of a Simplified Hierarchical File System

[0189]FIG. 14 shows an example of a simplified hierarchical file system.Most OS file management systems, including UNIX, Mac OS, MS-DOS,Windows, have a tree-like hierarchical structure.

[0190] Each disk drive (e.g., when a single HDD is divided into pluralpartitions, each partition corresponds to each disk drive) has one rootdirectory 401 serving as a parent for all this disk drive. To the rootdirectory, subdirectories 402 belong. The subdirectories 402 containscollections of file data 403.

[0191] In addition to the example, there may be a case where acollection of file data 403 exists just under the root directory 401 orplural subdirectories 402 are connected in series to form a complexhierarchical structure.

[0192] (A-2-4) The Contents of File Management Information Recorded onan Information Storage Medium

[0193] The file management information is recorded in logical blocks.The contents recorded in each logical block are chiefly the following:

[0194] Descriptive statement FID (File Identifier Descriptor) indicatinginformation on files.

[0195] It describes the types of file and file names (such as the rootdirectory name, subdirectory names, and file data names). In the FID, adescriptive statement indicating the contents of the subsequentcollection of file data and the recorded place of the contents of thedirectories (that is, the recorded places of the FE corresponding therelevant file explained below) is also written.

[0196] Descriptive statement FE (File Entry) indicating the recordedplace of the contents of files

[0197] Places on an information storage medium on which information onthe contents of collections of file data and on the contents ofdirectories (subdirectories) has been recorded are written.

[0198]FIG. 15 shows an excerpt of the descriptive contents of the fileidentifier descriptor. The details of it will be explained under (B-4)File identifier descriptor. FIG. 16 shows an excerpt of the descriptivecontents of the file entry. The details of it will be explained under(B-3) File entry.

[0199] The descriptive statement indicating the recorded places on theinformation storage medium uses a long allocation descriptor and a shortallocation descriptor of FIG. 17. The details of the short allocationdescriptor will be explained under (B-1-3) Short allocation descriptor.

[0200] As an example, the descriptive contents of information on thefile system structure of FIG. 14 recorded on an information storagemedium are as follows:

[0201] The contents of the root directory 401 are written in the logicalblock with logical block number 1.

[0202] In the example of FIG. 14, the root directory 401 contains only asubdirectory 402. As a result, information on the subdirectory 402 iswritten in a file identifier descriptor statement 404 as the contents ofthe root directory 401. Although not shown, information on the rootdirectory 401 itself is also written in a file identifier descriptorstatement in the same logical block.

[0203] Furthermore, in the file identifier descriptor statement 404 ofthe subdirectory 402, the recorded place of the file entry statement 405(in the example of FIG. 14, the second logical block) indicating wherethe contents of the subdirectory 402 are recorded is written in a longallocation descriptor statement (LAD (2)).

[0204] In the logical block with logical block number 2, a file entrystatement 405 indicating the place in which the contents of thesubdirectory 402 are recorded is recorded.

[0205] In the example of FIG. 14, the subdirectory 402 contains onlycollections of file data 403. As a result, the recorded place of a fileidentifier descriptor statement 406 indicating information on thecollections of file data 403 is essentially written as the contents ofthe subdirectory 402.

[0206] Furthermore, in the short allocation descriptor statement in thefile entry statement, it is written that the contents of thesubdirectory 402 are recorded in the third logical block (AD(3)).

[0207] The contents of the subdirectory 402 are recorded in the logicalblock with logical block number 3.

[0208] In the example of FIG. 14, the subdirectory 402 contains onlycollections of file data 403. As a result, information on thecollections of file data 403 are written in a file identifier descriptorstatement 406 as the contents of the subdirectory 402. Although notshown, information on the subdirectory 402 itself is also written in afile identifier descriptor statement in the same logical block.

[0209] Furthermore, in the file identifier descriptor statement 406about the collections of file data 403, the recorded place of the fileentry statement 407 indicating where the contents of the collections offile data 403 (in the example of FIG. 14, they are recorded in the forthlogical block) are recorded is written in a long allocation descriptorstatement (LAD (4)).

[0210] In the logical block with logical block number 4, a file entrystatement 407 indicating the place in which the contents 408, 409 of thecollections of file data 403 are recorded is recorded.

[0211] In the short allocation descriptor statement in the file entrystatement 407, it is written that the contents 408, 409 of thecollections of file data 403 are recorded in the fifth and sixth logicalblocks ((AD(5), AD(6)).

[0212] In the logical block with logical block number 5, information (a)408 on the contents of the collection of file data 403 is recorded.

[0213] In the logical block with logical block number 6, information (b)409 on the contents of the collection of file data 403 is recorded.

[0214] (A-2-5) Method of Accessing File Data According to theInformation Shown in FIG. 14

[0215] As explained briefly under (A-2-4) The contents of filemanagement information recorded on an information storage medium, in thefile identifier descriptors 404, 406 and the file entries 405, 407, thelogical block numbers indicating the pieces of information that followthose contents are written.

[0216] Just as a collection of file data is reached via subdirectories,starting from the root directory and going down levels of hierarchy, thecontents of the collection of file data are accessed by reproducing thepieces of information in logical blocks on the information storagemedium in sequence according to the logical block numbers written in thefile identifier descriptor and file entry.

[0217] Specifically, to access the collection of file data 403 accordingto the information shown in FIG. 14, the first logical block informationis first read. Since the collection of file data 403 exists in thesubdirectory 402, the first logical block information is searched forthe file identifier descriptor 404 of the subdirectory 402. After LAD(2) has been read, the second logical block information is readaccording to LAD (2).

[0218] Because only one file entry statement is written in the secondlogical block, AD (3) is read from the block and control goes to thethird logical block. The third logical block is searched for the fileidentifier descriptor 406 written about the collection of file data 403.Then, LAD (4) is read. According to LAD (4), control proceeds to thefourth logical block. Because only one file entry statement 407 iswritten in the fourth logical block, AD (5) and AD (6) are read and thelogical block numbers (5 and 6) in which the contents of the collectionof file data 403 are recorded is found.

[0219] The contents of AD (*) and LAD (*) will be explained in detailunder (B) Concrete description of the contents of each descriptivestatement in the UDF.

[0220] (A-3) Features of the UDF

[0221] (A-3-1) Explanation of the Features of the UDF

[0222] The features of the UDF will be explained in comparison with theFAT used in the HDD, FDD (Floppy Disk Drive), and MO (Magneto Optics):

[0223] (1) The UDF has large minimum units (including the minimumlogical block size and the minimum logical sector size) and suitable torecord video information or music information that has a large amount ofinformation to be recorded.

[0224] Specifically, the size of a UDF logical sector (block) is aslarge as 2048 bytes, whereas the size of a FAT logical sector is 512bytes.

[0225] (2) With the UDF, the file management information can be recordedin a distributed manner at arbitrary places on the disk, whereas withthe FAT, a management table (file allocation table) for allocating filesto the information storage medium is recorded intensively in a localplace on the information storage medium.

[0226] Specifically, with the UDF, the recorded places on the diskconcerning the file management information and file data are written aslogical sector (block) numbers in the allocation descriptor.

[0227] With the FAT, the file management information is controlledcentrally in the file management area (file allocation table).Therefore, the FAT is suitable for an application that needs to changethe file structure frequently (particularly to rewrite frequently).Since the FAT is recorded in a local place, it is easy to rewrite themanagement information. Furthermore, since the recorded place of thefile management information (file allocation table) has been determined,the recording medium is required to have high reliability (e.g., have nodefective area).

[0228] Since, with the UDF, the file management information isdistributed over the disk, this leads to few great changes in the filestructure. Therefore, the UDF is suitable for an application where newfile structures are added later (particularly a postscript application).Namely, In adding a file structure, the present file managementinformation has only to be changed in fewer places.

[0229] Since the recording places of the distributed file managementinformation can be specified arbitrarily, recording can be done avoidingcongenital defective portions. Recording the file management informationin arbitrary places also enables all the file management information tobe concentrated in one place, which is the advantage of the FAT.Consequently, the UDF can be considered to be a more versatile filesystem.

[0230] (B) Concrete Description of the Contents of Each DescriptiveStatement (Descriptor) in the UDF

[0231] (B-1) Descriptive Statement of Logical Block Number

[0232] (B-1-1) Allocation Descriptor

[0233] As described under (A-2-4) The contents of file managementinformation recorded on an information storage medium, a descriptivestatement that is part of a file identifier descriptor or a file entryand describes the place (logical block number) in which the informationfollowing that file identifier descriptor or file entry is recorded iscalled a allocation descriptor. There are two types of allocationdescriptor: a long allocation descriptor and a short allocationdescriptor.

[0234] (B-1-2) Short Allocation Descriptor

[0235] As shown in FIG. 17, in the length of extent 410, the number oflogical blocks is expressed in four bytes. In the position of extent411, the relevant logical block number is expressed in four bytes. Inthe descriptive statement, the description is simplified and written inAD (logical block number).

[0236] (B-2) Unallocated Space Entry

[0237] This is a descriptive statement that writes the unrecorded extentdistribution on an information storage medium in a short descriptor foreach extent and arranges the descriptors. It is used in a space table(see FIGS. 12A, 12B, 13A and 13B). Specifically, in this statement, adescriptor tag (representing the identifier for the contents of thedescription), an ICB tag (representing the file type), and the totallength of the allocation descriptor train (the total number of bytes infour bytes) are written. The file type=1 in the ICB tag means anunallocated space entry. The file type=4 means a directory and the filetype=5 means file data.

[0238] (B-3) File Entry

[0239] This is the statement explained under (A-2-4) The contents offile management information recorded on an information storage medium.As shown in FIG. 16, in this statement, the following are written: adescriptor tag 417 (representing the identifier for the contents of thedescription, 261 in this case), an ICB tag 418 (representing the filetype, its contents being the same as (B-2)), permission 419(representing information on permission to record, reproduce, and deletefor each user, mainly used for assuring file security), and anallocation descriptor 420 (writing the location in which the contents ofthe relevant file are recorded for each extent by placing shortallocation descriptors side by side).

[0240] (B-4) File Identifier Descriptor

[0241] This is the statement explained under (A-2-4) The contents offile management information recorded on an information storage medium.AS shown in FIG. 15, in this statement, the following are written: adescriptor tag 421 (representing the identifier for the contents of thedescription, 257 in this case), file characteristic 422 (representingthe type of file, meaning one of parent directory, directory, file data,and file delete flag), an information control block 423 (the FE locationcorresponding to the file is written in a long allocation descriptor), afile identifier 424 (directory name or file name), padding 437 (dummyareas added to adjust the total length of the file identifierdescriptor, in all of which “0” is normally written).

[0242] There are two methods of managing the unrecorded locations on aninformation storage medium:

[0243] Space Bit Map Method

[0244] A recorded flag or an unrecorded flag is set in a bit map mannerfor all the logical blocks in the recording area on the informationstorage medium using the space bit map descriptor 470 (see FIGS. 12A and12B).

[0245] Space Table Method

[0246] All the unrecorded logical block numbers are written as a list ofshort allocation descriptors using the form of writing an unallocatedspace entry 471 (see FIGS. 12A and 12B).

[0247] In the embodiment, the two methods are written in FIGS. 12A, 12B;13A and 13B for the sake of explanation. Actually, however, both of themethods are hardly used (recorded on the information storage medium) atthe same time. Only one of the methods is used.

[0248] An outline of the contents of the principal directories writtenin FIGS. 12A, 12B, 13A and 13B is as follows:

[0249] Beginning extent area descriptor 445 . . . Indicates the startposition of volume recognition sequence 444.

[0250] Volume structure descriptor 466 . . . Describes the contents ofthe volume 444.

[0251] Boot descriptor 447 . . . Describes the contents of processing ina boot operation.

[0252] Terminating extent area descriptor 448 . . . Indicates the endposition of the volume recognition sequence 444.

[0253] Partition descriptor 450 . . . Indicates the partitioninformation (including size). As a general rule, the DVD-RAM has onepartition per volume.

[0254] Logical volume descriptor 454 . . . Describes the contents of thelogical volume.

[0255] Anchor volume descriptor pointer 458 . . . Indicates' therecorded locations of the main volume descriptor sequence 449 andreserve volume descriptor sequence 467.

[0256] Reserved (00h bytes all) 459 to 465 . . . Records specificdescriptors. To secure logical sector numbers, adjusting areas in all ofwhich “0” is recorded are provided between them.

[0257] Reserve volume descriptor sequence 467 . . . Serves as a backuparea for the information recorded in the main volume descriptor sequence449.

[0258] Using FIGS. 18A to 18D, a file position setting method in aconventional method that has no unrecorded area in a video file will beexplained. Consider a case where two PC files and a single video filehave been recorded in the data area 1004 on an information storagemedium as shown in FIG. 18A. In FIGS. 18A to 18D, LBN means a logicalblock number.

[0259] When the LBNs at the start position of the individual files areA, F, and C, the recording positions on the file entry of a PC file areFE[AD(A)] and FE[AD(F)] respectively by using the notations in FIGS.12A, 12B, 13A and 13B or FIGS. 14 and 16. Since in FIG. 18A, video file#1 is recorded together in one place, this makes it possible to writeusing one extent. As a result, the file entry corresponding to the fileis FE[AD(C)].

[0260] Next, consider a case where the logical blocks with LBNs from Dto E in video file #1 are erased. With the conventional method, anunrecorded area is not allowed to exist in a file. Therefore, therecorded place in video file #1 on the information storage medium isdivided into two places, as shown in FIG. 18B.

[0261] As a result, since the extent describing the allocation(recording positions) of the video file is divided in two, the fileentry for the video file is FE[AD(C), AD(E)]. Under the UDF, thecontinues recording and playback of video information are not managed.At the stage in FIG. 18B, the areas with the LBNs from D to E areconsidered as an unrecorded area and the recording of another file intothe area is permitted. For this reason, PC file #3 may be recorded inthe unrecorded area as shown in FIG. 18C.

[0262] In a case where another piece of video information cannot berecorded in the logical blocks with the LBNs from D to E, regardless ofan attempt to record the piece of video information, it is recorded asvideo file #2, another video file, in the place with the LBNs startingat G, far away from video file #1, as shown in FIG. 18D. Specifically,with the conventional method that permits no unrecorded area to exist,video files are scattered over the information storage medium. When allthe video files are reproduced continuously, continuous playback isdifficult because of the access time of the optical head. Similarly,with the conventional method, continues recording is difficult.

[0263] Using FIGS. 19A to 19D, a method, related to the presentinvention, of setting a file recording position on the informationstorage medium in a case where an unrecorded area is allowed to exist ina video file will be explained. FIG. 19A corresponds to FIG. 18A. In theembodiment, when the logical blocks with the LBNs from D to E areerased, the file size of the video file does not change because videofile #1 has an unrecorded area as shown in FIG. 19B. The file entry tothe video file remains unchanged, FE[AD(C)]. As a result, when a new PCfile is recorded, any PC file will not be inserted into video file #1,as shown in FIG. 19C.

[0264] Furthermore, when video information is additionally recorded byvideo recording, the additional recording information is recorded in theunrecorded area with the LBNs from D to E. The unrecorded area thenchanges to an additional recording area. As described above, with theinformation recording/reproducing apparatus of FIG. 11, the file systeminformation about the UDF need not be changed each time a small part ofthe video information is erased or additional recording is done by videorecording. This facilitates the processing of the informationrecording/reproducing apparatus. Moreover, when the amount of videoinformation increases, the video file size becomes larger.

[0265] That is, the unrecorded area with the LBNS from B to C of FIG.19C is absorbed by video file #1. While the video file of FIG. 19C hasonly one extent AD(C), the video file of FIG. 19D has an additionalextent AD(A), providing a file entry of FE[AD(C), AD(B)].

[0266] Information about each cell of FIG. 10 is recorded in the celltime control information 1104 as shown in FIG. 3F. As shown in FIG. 3G,its contents is made up of the following:

[0267] Cell time information #1 1113 to #m 1115 Information on each ofthe cells 1121 to 1124.

[0268] Cell time search information 1112 Map information indicating theposition (AV address) in which the corresponding cell time informationis written when a specific cell ID is specified.

[0269] Cell time control general information 1111 Information about allthe cell information.

[0270] Each piece of cell time information contains cell time generalinformation #m 1116 and cell VOBU table #m 1117 as shown in FIG. 3H.

[0271]FIG. 8 illustrates the data structure of the cell timeinformation. It is made up of the cell time control general information1111 indicating the recording position of each cell 84 of FIG. 7 in therecording/reproducing video data RWVIDEO_OBJECT.VOB (corresponding tothe contents of the video object 1012 in FIG. 3D) and the cell timesearch information 1112 indicating the pieces of LBN (logical blocknumber) information 2011 to 2013 in the place where the cell timeinformation is recorded, in the recording/reproducing video managementdata RWVIDEO_CONTROL.IFO (corresponding to the data in the controlinformation 1011 of FIG. 3D).

[0272] In the cell time control general information 1111, writing isdone in the recording position using the AV address. While in FIG. 8,the AV addresses 2002, 2004, 2006 at the begin positions and therespective data sizes 2003, 2005, 2007 are written as the positionalinformation for each cell, the AV addresses 2023, 2025, and 2027 at theend positions are written in place of data size in another example ofFIG. 9.

[0273] The contents of the cell time information recorded in therecording/reproducing video management data RWVIDEO_CONTROL.IFO (thesame as the data in the control information 1011 of FIG. 3D) of FIG. 4are shown in FIG. 20.

[0274] Specifically, the cell time general information 1116 indicatesgeneral information on each cell. The playback speed 2033 is recordedfor each cell, enabling variable speed playback. For example, only theCM portion can be played back at high speed.

[0275] Furthermore, the password 2034 and permission 2035 can berecorded in cells, assuring security and enabling parental lock. Thecontents of the permission setting for each cell are as shown in FIG.20. Moreover, for the erase level restorable by UNDO like the dustbin ona PC, the user can set erase specify information 2036 or erase/overwritepriority rank information 2037 indicating the order of priority in whicherasing is done automatically according to the remaining amount in videorecording.

[0276] The cell VOBU table 117 of FIG. 20 is used for time codes.Specifically, time codes are expressed by a combination of the number ofvideo frames 2042, 2044, 2046 contained in a cell and the data sizes(the number of sectors used) for the respective individual VOBUs 2041,2043, 2045. Use of this notation enables a time code to be expressed bya very small amount of information. Hereinafter, an accessing methodusing the time codes will be explained.

[0277] 1. The user specifies the desired cell and the time at which thecell is to be accessed.

[0278] 2. According to the specified time, the MPU of the microcomputerblock 30 of FIG. 11 calculates the video frame number from the cellstart position of the corresponding video frame.

[0279] 3. The MPU calculates the cumulative total of the number of videoframes 2042 to 2046 for each VOBU from the cell head shown in FIG. 20and determines which video frame in which VOBU the user-specified videoframe falls on, counting from the first VOBU.

[0280] 4. The recording positions of all the data items in the cell onthe information storage medium are determined from the cell time controlgeneral information of FIG. 8 or 9.

[0281] Using FIGS. 21A to 21D, a detailed explanation of the datastructure of the video file and an explanation of an additionalrecording method by partial erasing or video recording will be given. Ablock of information recorded continuously for a VOB in a video file onthe information storage medium is expressed in extents as with the UDF.In FIG. 21A, each of VOB #1 and VOB #2 is composed of one extent (extent#a and extent #b, respectively).

[0282] In FIG. 21A, like the files in the dustbin on the PC, cell D hasbeen specified by the user for erasure. It is deleted from the PGCinformation of FIG. 10B, so the user cannot see it during playback.However, taking cell D out of the dustbin enables cell D to beregistered in the PGC information of FIG. 10B, which enables the user toreproduce it again.

[0283] When the first portion of cell B in FIG. 21A is specified by theuser for complete deletion, the MPU of FIG. 11, receiving the completedelete range of the portion from the user in the form of timeinformation (as to from what second to what second the portion isdeleted completely), refers to the cell VOBU table 1117 of FIG. 20 anddetermines which VOBU the relevant time range corresponds to.

[0284] Next, the VOBU including the boundary time of the completedeletion (the fourth VOBU from the head in cell B corresponds to thatVOBU in FIG. 21A) is removed from the objects of complete deletion. Bythis method, the MPU of FIG. 11 calculates the VOBU to be deletedcompletely and deletes the relevant portion as shown in FIG. 21B.

[0285] Thereafter, when receiving information that the user wants torecord a very large amount of information additionally, the MPU of FIG.11 maps all the AV addresses in the video file and deletes the AVaddresses for the already recorded portions from the positionalinformation about the VOB of FIG. 22. Then, the addresses for theunrecorded areas are found from the remaining AV addresses. The sizes ofall the unrecorded areas are totaled and the result is compared with theadditional recording video information size previously specified by theuser.

[0286] If the totaled size of all the unrecorded areas is insufficient,the delete-specified area is erased completely as shown in FIG. 21C. Ifthe size is still insufficient, the delete/overwrite priority rankinformation 2037 is read from the cell time general information 1116 ofFIG. 20 and deleting is done, starting at the highest level of priority.

[0287] As a result, the data in VOB #3 is filled into the blankunrecorded area as shown in FIG. 21D. In FIG. 21D, cell E is divided andrecorded in two separate places. In FIG. 21D, the data in VOB #3 isdivided into three extents (extent #c, extent #d, extent #e), which arethen recorded.

[0288]FIG. 22 shows the data structure of the VOB control information1106 of FIG. 3F. The VOB control information 1106 is made up mainly ofthe positional information on VOBs and information indicating therelationship between pieces of cell information for each VOB. As shownin FIGS. 21A to 21D, one VOB can be distributed over a video file.

[0289] A block of information recorded continuously in a video file in aVOB is expressed by extents as in the UDF. Since the AV address size inthe video file is known beforehand, when the positional information onall the VOBs of FIG. 22 is deleted from the mapping of all the AVaddresses, the remaining AV addresses are for the unrecorded areas inthe video file.

[0290] The various operations of the information reproducing apparatusor information recording/reproducing apparatus will be explained.

[0291] Processing When the User has Deleted the Recording/ReproducingVideo Data by Mistake

[0292] After an information storage medium (an optical disk 1001) isinstalled, the information recording/reproducing section 32 reproducesrecording/reproducing video management data RWVIDEO_CONTROL.IFO.Thereafter, it retrieves recording/reproducing video dataRWVIEO_OBJECT.VOB, still picture data RWPICTURE_OBJECT.POB, thumbnailpicture data RWTHUMBNAIL_OBJECT.POB, and audio data RWAUDIO_OBJECT.AOBon the assumption that the user has deleted the recording/reproducingvideo data by mistake. If some data item is missing, the DVD videorecorder display section 48 is caused to display the message “A specificfile is not found.”

[0293] Video File Size Setting Method at the Beginning

[0294] A new information storage medium (an optical disk 1001) isinstalled for the first time and the information recording/reproducingsection 32 reproduces recording/reproducing video management dataRWVIDEO_CONTROL.IFO. Finding that recording/reproducing video dataRWVIDEO_OBJECT.VOB has not been created, the MPU causes the DVD videorecorder display section 48 to display the message “A video recordablearea is going to be created. How many hours of video recording do youwant to set for standard setting?” and requests the user to answer. Onthe basis of the answer from the user, the MPU calculates the video filesize automatically and registers a file for recording/reproducing videodata RWVIDEO_OBJECT.VOB in the UDF.

[0295] Address Conversion Between LBN and AV Address is Carried OutUsing the DMA Information

[0296] When a DVD-RAM is used as an information storage medium, the DMAarea is read and address conversion between LBN and AV address iscarried out. A means for reading defect position information from theinformation storage medium corresponds to the informationrecording/reproducing section 32 of FIG. 11. A conversion means foreffecting address conversion between logical address and AV address fromthe defective position information obtained by the means for readingdefective position information corresponds to the MPU of FIG. 11.

[0297] Interlocking Process of UDF and AV Address According to the VideoFile Size Change

[0298] As shown in FIG. 19D, as video recording is repeated, theinitially set video file size may have to be changed. As a means forcreating file system change information according to the video file sizechange, the MPU of FIG. 11 calculates change information in the UDF.Then, it causes the information recording/reproducing section 32 torecord the result of the calculation on the information storage medium(optical disk 1001). The MPU also functions as a means for creatingchange information on the AV address setting state in the video fileaccording to the file system change information. It causes theinformation recording/reproducing section 32 to record the createdchange information in the recording/reproducing video management dataRWVIDEO_CONTROL.IFO of FIG. 4 on the information storage medium.

[0299] Reallocating Cells/VOB Addresses as a Result of the Video FileSize Change

[0300] The MPU of FIG. 11 further functions as a means for creating filesystem change information according to the video file size change. Theinformation recording/reproducing section 32 corresponds to a means forchanging (rewriting) at least part of the address information about thecells recorded on the information storage medium or the addressinformation about VOBs according to the file system change information.

[0301] Determining the Unrecorded Position on the Disk from the Cell orVOB Address Allocation Information

[0302] This operation is the same as explained in FIG. 22. A means forreading information on a set of the begin address and cell size for eachVOB or each cell or on a set of the begin address and end address fromthe information storage medium corresponds to the informationrecording/reproducing section 32 of FIG. 11. A means for extracting theaddress for the unrecorded area in the video file from the read addressinformation for each VOB or the read address information for each cellcorresponds to the MPU.

[0303] Executing a Permission Process According to the PermissionSetting in Cells or VOBS

[0304] Video files containing at least video information and managementfiles are recorded on an information storage medium. For the videofiles, information is recorded in files. The information recorded in thefiles can be read by playback. The management files have managementinformation about a control method of reproducing the video informationrecorded in the video files.

[0305] The video information in the video files contains blocks ofinformation in cells or VOBs. In the information storage medium, thepermission setting information is recorded in the management files incells or VOBs.

[0306] A means for reproducing the permission information from theinformation storage medium corresponds to the informationrecording/reproducing section 32. The MPU functions as a display controlmeans for providing display control of reproduced pictures according tothe reproduced permission information. In addition, a recording/deletingmeans for recording and deleting pictures on the basis of the reproducedpermission information also corresponds to the MPU.

[0307] Changing the Size of Cells or VOBs on the Basis of the VOBU Unit

[0308] The MPU of FIG. 11 functions as a first judging means for judgingthe cell or VOB related to the video portion to be deleted when part ofthe video information in the video file is deleted. Using the cell VOBUtable 1117 of FIG. 20, the MPU judges all the VOBUs constituting thecells or VOBs extracted by the first judging means (MPU).

[0309] A first decision means (MPU) and a recording means for changingand recording the recording/reproducing management data by changing theVOBU information constituting the cells or VOBs on the basis of theresult from the first decision means (MPU) correspond to the informationrecording/reproducing section 32 of FIG. 11. The first decision meansjudges the VOBU corresponding to the picture portion to be deleted andremoves from the VOBUs to be deleted the VOBU in which the boundaryposition of the picture portion to be deleted coincides with the centralposition. For the cells or VOBs judged by the first judging means (MPU),the first decision means removes the VOBU to be deleted judged by athird judging means (MPU) from the VOBUS constituting the cells or VOBsjudged by the second judging means (MPU).

[0310] With the embodiment, use of only one video file recordable andreproducible on an information storage medium enables the user to beinformed of abnormality at the beginning of or before playback when theuser has deleted a video file by mistake. With the conventional DVDvideo disk which allows more than one video file to exist, when the userhas deleted one of the video files by mistake, the informationreproducing apparatus or information recording/reproducing apparatusstarts playback without sensing the mistake. It does not display themistake until starting to reproduce the deleted video file. This causesinconvenience to the user. The present invention eliminates thisproblem.

[0311] Each of the information reproducing apparatus and informationrecording/reproducing apparatus accesses only the video file(RWVIDEO_OBJECT.VOB of FIG. 4) whose file name has been specified inrecording and reproducing video information. Therefore, even if the userhas put a similar video file (under subdirectory RWV_TS) by mistake, aserious adverse effect can be avoided because each of the informationreproducing apparatus and information recording/reproducing apparatusignores the file.

[0312] Only one recordable, reproducible video file is allowed to existon an information storage medium and all the video information recordedin the video file is set by a single PGC so that all the videoinformation may be reproduced in sequence. This makes it easy for theuser familiar with the way of recording a single tape, such as a VTRtape to use the apparatus.

[0313] The above method makes it easy to display all the recorded videoinformation in such a manner that all the video information is a stringof information like a single tape. Moreover, the method enables the userto operate the apparatus as if to record, delete, or reproduce the datain a specific place on a single tape.

[0314] As a result of allowing an unrecorded area to be defined in thevideo file, the following can be done:

[0315] (a) The deleted place can be changed to an unrecorded areawithout decreasing the video file size, when part of the data in thefile is deleted.

[0316] (b) Additional data can be recorded in an unrecorded area in thefile without changing the total file size.

[0317] As a result, the video file size need not be changed each timepart of the video information is deleted or additional video informationis recorded. This enables the data to be written only in the portion tobe changed, such as the deleted place or the additional data recordedplace in the unrecorded area, without modifying the portion not to bechanged in the video file.

[0318] When the contents of a video file of a very large size arechanged, the process, related to the invention, of changing the dataonly in the portion to be changed in the video file shortens remarkablythe time required to change the data on the information storage medium,as compared with the conventional method of recording all the filesagain.

[0319] Use of unrecorded areas in a video file and playback sequenceinformation (PGC) about all the video information reproducible in thevideo file makes it possible to set a video information recording placein the video file on the application software side that processes thevideo file, independent of the file system (UDF). As a result, a videoinformation recording place can be set according to the playbacksequence information (PGC), which makes it easy to record and reproducethe video information continuously.

[0320] The file system, such as the UDF or FAT, is allowed to set therecording places (recording addresses: LBNs (Logical Block Numbers)) ofthe individual files. However, since the UDF or FAT is given only thefine names and file sizes, it allocates sequentially the recordingpositions of the file sizes given to the blank areas on the informationstorage medium.

[0321] Specifically, since no PGC information is given to the UDF orFAT, recording places suitable for the continues recording orreproducing of video information cannot be set. Giving an unrecordedarea in the video file makes it unnecessary to change the video filesize when part of the video information is deleted or a small amount ofvideo information is added.

[0322] As a result, on the file system, such as the UDF or FAT, therecording place (recording address) of the video file is not changed inadding a small amount of video information or deleting part of the videoinformation. The recording place of the additional video information orthe partially deleted place can be managed on the application softwareside that processes the video file.

[0323] Specifically, the application software side tells the file systemside, such as the UDF, about the LBNs for the place in which partialdeletion or overwriting is to be effected and carries out a partialrewriting process. Having the playback sequence information (PGC) aboutall the video information reproducible in the video file, theapplication software side can specify addresses that allow continuesrecording and reproducing of the video information according to the PGCinformation.

[0324] Only one video file is allowed to exist on an information storagemedium and an unrecorded area can be defined in the video file. As aresult, even when a video file in which video information is recordedand a computer file in which general computer data is recorded areallowed to exist on the same information storage medium in a mixedmanner, the video information can be concentrated and recorded in aspecific place on the information storage medium, which makes it easy torecord and reproduce the video information continuously.

[0325] Consider a case where a video file and a computer file arerecorded on the same information storage medium in a mixed manner.Addresses (LBNs) indicating the recording places on an informationstorage medium for computer files are set on a file system, such as theUDF. As a result, computer files may be scattered over the informationstorage medium.

[0326] Thereafter, when the video file is recorded, the video file maybe entered as a collection of extents separated away from each other insuch a manner that they are interspersed between the scattered computerfiles. In the case of the conventional file structure with no unrecordedarea in a file, the video file size is changed each time part of thevideo information in the file is deleted or additional video informationis recorded. Whenever the video file size changes, the allocationsindicating the recording places on the information storage medium (thedistribution of extents in which the video file is recorded) change.

[0327] For example, a very-large-sized video file (to the allocationdescriptor of whose file entry consecutive addresses are allocated) iscreated by hours of video recording in such a manner that the video fileis localized in one place on the information storage medium. Thereafter,when the middle of the recorded video information is deleted, thepartial deletion separates the allocations of the video files into twoplaces on the information storage medium when the file has no unrecordedarea as in the prior art.

[0328] Thereafter, PC data may be recorded in the deleted portion. Whenthe video file size is made larger by video recording after the PC datahas been recorded in the place, additional video information has to berecorded in a position far away from the recording area of the existingvideo file on the information storage medium. The interspersing of asingle video file in separate positions on the information storagemedium has an adverse effect on the continues recording and reproducingof the video information.

[0329] With the present invention, securing an unrecorded area in thesame video file prevents the recorded positions of the video file on theinformation storage medium from interspersing even when partial deletionand additional video recording are repeated. This makes it easy torecord and reproduce the video information continuously.

[0330] Since the begin address and size information for each cell or VOBare recorded together on an information storage medium, the cell (orVOB) allocation distribution in a video file can be sensed at highspeed. As a result, the location of the unrecorded area in the videofile can be sensed immediately.

[0331] This speeds up a series of video recording start processes ofreproducing the management data (RWVIDEO_CONTROL.IFO in FIG. 4), sensingthe unrecorded place in the video file, and starting video recording.When each piece of video information is contained in a separate videofile as in the example of FIG. 1, there is no unrecorded area in thevideo file. Only when a method of containing all the video informationrecorded on an information storage medium in a single video file is usedas in the present invention, an unrecorded area appears in the videofile and information on the allocation distribution of cells in thevideo file is needed.

[0332] Since the correlation between AV addresses and LBNs changes asthe video file size changes, the addresses of the cells and VOBs have tobe changed partially. Since the address information about the cells andVOBs recorded in the cell time general information and VOB controlinformation is written as a set of each begin address and size, eachbegin address has only to be changed when the addresses are changed.This reduces the amount of changed management data items.

[0333] In the DVD video disk standard, the begin address and end addressfor a cell piece are recorded in the video title set cell piece VTS_CPIin the video title set address table VTS_C_ADT. In this case, whenaddresses are changed, both the begin address and the end address mustbe changed. With the above method, the cell size or VOB size need not bechanged, which reduces the number of changed places by half.

[0334] Permission can be set closely in cells or VOBs. In the DVD videodisk standard, the parental lock function is carried out on a videotitle basis or a PGC basis. With the UDF, permission can be set file byfile.

[0335] With the present invention, since there are a single video fileand a PGC covering all the video information on an information storagemedium, neither the close setting of permission according to the videoinformation nor the setting of parental lock nor security management canbe effected. However, the invention provides permission setting flagsfor each cell or each VOB, enabling the close setting of permission.

[0336] The cell size or VOB size is changed on a VOBU basis as a resultof partial deletion of the video information, which makes re-encodingunnecessary. Only the management data (e.g., RWVIDEO_CONTROL.IFO) has tobe changed, speeding up the change operation.

[0337] Since conventional DVD video disks are for playback only, thecell size or VOB size need not be changed by partial deletion of thevideo information. Video-recordable information storage mediums of thepresent invention, however, require the change of the cell size or VOBsize. As compared with a case where the VOBU is created again(re-encoded) each time the cell size or VOB size is changed, the methodof the present invention enables the cell size or VOB size to be changedeasily at high speed.

[0338] Since a VOB on the information storage medium can be recordedover a cluster (extent) of one or more video recording areas, the VOBcan be recorded over a cluster (extent) of plural blocks of videoinformation in such a manner that it intersperses between the pieces ofvideo information scattered in the video file.

[0339] With the data structure of the information storage medium of theinvention, since all the video information is recorded in a single videofile, pieces of recorded video information are scattered in the videofile as video recording and partial deletion are repeated many times. Asa result, many small-sized unrecorded areas are scattered in the videofile.

[0340] When VOBs are recorded in consecutive address areas, places inwhich large VOBs can be recorded are limited, reducing the recordablecapacity of the video file. By enabling a single VOB to be recorded overa cluster (extent) of plural video areas separate from each other in thevideo file, video recording can be done without wasting many small-sizedunrecorded video areas scattered in the file.

[0341]FIGS. 23A to 23H illustrate another example of a hierarchicalstructure of the information recorded on an optical disk 1001 serving asan information storage medium. FIGS. 23A to 23C correspond to FIGS. 3Ato 3C explained earlier. The contents of the audio & video data area1009 in FIG. 23C correspond to those of the audio & video data area 1009in FIG. 3C as described below.

[0342] The navigation data RTR_VMG 2201 in FIG. 23D corresponds to thecontrol information 1011 in FIG. 3D. The movie video recording objectRTR_MOV.VRO 2202 in FIG. 23D corresponds to the video object 1012 inFIG. 3D.

[0343] The still picture video recording object RTR_STO.VRO 2203 in FIG.23D corresponds to the picture object 1013 in FIG. 3D. The stillpicture-added video recording object RTR_STA.VRO 2204 in FIG. 23Dcorresponds to the audio object 1014 in FIG. 3D.

[0344] Neither the maker specification object MSP.VOB 2205 nor otherstream object AST.VOB 2206 in FIG. 23D is shown in FIG. 3D. In theexplanation, RTR is an abbreviation of real time recording.

[0345] The navigation data RTR_VMG 2201 is used to record, reproduce, oredit an AV stream (one or more video object set VOBS). The navigationdata RTR_VMG 2201 contains all the necessary navigation data including asingle management information file called RTR_IFO.

[0346] Specifically, as shown in FIG. 23E, the navigation data RTR_VMG2201 includes RTR video manager information RTR_VMGI 2210, a movie AVfile information table M_AVFIT 2211, a still picture AV file informationtable S_AVFIT 2212, an original PGC information ORG_PGCI 2213, auser-defined PGC information table UD_PGCIT 2214, a text data managerTXT_DT_MG 2215, and a manufacturer information table MNFIT 2216.

[0347] These seven types of information 2210 to 2216 are written in thefile RTR_IFO in the order in which they have been described above. Mostof the information written in the file RTR_IFO is stored in the RAM ofthe microcomputer block 30 of FIG. 11.

[0348] In the RTR video manager information RTR_VMGI 2210, the basicinformation (similar information to the video manager information VMGIin the DVD video ROM) on the RTR disk (optical disk 1001) is written. Inthe movie AV file information table M_AVFIT 2211, a movie AV filecorresponding to the movie video recording object RTR_MOV.VRO of FIG. 24is written.

[0349] In accordance with the AV data control information 1101 in thecontrol information 1011 of FIG. 3D, the navigation data RTR_VMG 2201 ofFIG. 23D includes a movie AV file information table M_AVFIT 2211.

[0350] As shown in FIG. 23F, the movie AV file information table M_AVFIT2211 includes a movie AV file information table M_AVFITI 2220, one ormore pieces of movie VOB stream information M_VOB_STI #1 TO M_MOB_STI #n2221, and movie AV file information M_AVFI 2222.

[0351] In the movie AV file information M_AVFI 2222, information on themovie AV file whose file name is movie video recording objectRTR_MOV.VRO is written.

[0352] As shown in FIG. 23G, the movie AV file information M_AVFI 2222includes general information M_AVFI_GI 2230 in the movie AV fileinformation M_AVFI, one or more movie VOB information search pointersM_VOBI_SRP #1 to M_VOBI_SRP #n 2231, and one or more pieces of movie VOBinformation M_VOBI #1 2232 to M_VOBI #n 2233.

[0353] An n number of pieces of movie VOB information M_VOBI #1 2232 toM_VOBI #n 2233 in the movie AV file information M_AVFI 2222 are writtenin the same order in which the VOB data items stored in the move AVfile.

[0354] As shown in FIG. 23H, each of the pieces of movie VOB informationM_VOBI #1 2232 to M_VOBI #n 2233 includes movie VOB general informationM_VOBI_GI 2240, seamless information SMLI 2241, audio gap informationAGAPI 2242, and time map information TMAPI 2243. The time mapinformation TMAPI 2243 includes the cell general time information 1116and cell VOBU table 1117 shown in FIG. 3H.

[0355]FIG. 24 shows an example of a directory structure of theinformation (data file) recorded on an optical disk 1001 using the datastructure shown in FIGS. 23A to 23H. Even when the optical disk 1001 andits reproducing apparatus use the data structure shown in FIGS. 23A to23H, the user cannot see the data structure. The data structure the usercan perceive is a hierarchical file structure as shown in FIG. 24.

[0356] Specifically, according to the types of data recorded in the dataarea 1004 of FIG. 23B, the DVD_RTR directory, VIDEO_TS directory,AUDIO_TS directory, and computer data file directories are displayed inthe form of menu screens or icons on the root directory screen (notshown).

[0357] The DVD_RTR directory of FIG. 24 corresponds to the RWV_TS fileof FIG. 4. Under the DVD_RTR directory, the following have been stored:the file RTR.IFO for navigation data RTR_VMG of FIG. 23D, a backup fileRTR.BUP for the RTR.IFO, a file RTR_MOV.VRO for the movie video objectRTR_MOV.VOB, a file RTR_STO.VRO for the still picture video objectRTR_STO.VOB, a file RTR_STA.VRO for the still picture-added audio objectRTR_STA.VOB, a file MSP.VOB for the maker specification object, and afile AST.SOB for other stream objects.

[0358] The file RTR_IFO shall exists as long as any contents compliantto this specification are recorded. The navigation data is recorded inthe file RTR_IFO.

[0359] Since the stream data categorized in movie VOB are recorded inthe file RTR_MOV.VRO. Therefore, as long as any movie VOB exist, thisfile shall exist.

[0360] The stream data categorized in still picture VOB are recorded inthese two files RTR_STO.VRO and RTR_STA.VRO. The file RTR_STO.VRO isused to record original VOBs which consists of a video part including anoptional sub-picture unit an optional audio part associated with thevideo part.

[0361] The file RTR_STA.VRO is used to record additional audio partwhich represents an audio stream recorded in after recording. The audiopart recorded in the file RTR_STA.VRO shall be used in combination withsome of the video part recorded in the file RTR_STO.VRO.

[0362] The file RTR_STO.VRO shall exist as long as any still picture VOBexists, and file RTR_STA.VRO shall exist as long as any additional audiopart to be presented with some video part recorded in the fileRTR_STO.VRO exists.

[0363] Among other PGCs, only original PGC includes stream data storedin the file VRO. Then, only one original PGC shall exist in the disk.

[0364] The user-defined PGC is a chain of part of programs. However, itcontains only navigation data and each part of program refer to streamdata belonging to the original PGC. Therefore, creating or deleting anuser-defined PGC does not affect the original PGC at all.

[0365] A VOBU is a basic unit of a VOB which consists of one or moreGOPs of video data. It has a presentation time period between 0.4seconds to 1 second is case of movie VOB. In case of still picture VOB,a VOBU contains only one video picture, and the whole VOB becomes aVOBU.

[0366] There is an exceptional rule that the last VOBU of a movie VOBmay have a presentation time period less than 0.4 seconds period.

[0367] A cell in the original PGC is called original cell. A cell in theuser-defined PGC is called user-defined cell. The two types of cells aredefined each for movie VOB and still picture VOB. When the cell type isfor movie VOB, the cells shall only refer to a whole or a part of themovie VOB.

[0368] The PGCI is a data structure to represent a total presentation ofa PGC. This is used both for the original PGC and user-defined PGC. Theuser-defined PGC has only PGCI. The cells in the PGCI refer to VOBs inthe original PGC. The total presentation of the PGC is described as apresentation sequence of cells defined in the PGCI.

[0369] The original PGC consists of PGCI, VOBI, and VOB. The PGCIconsists of either one cell or a sequence of more than one cell.Therefore, the total presentation of the original PGC is a sequence ofcell presentation. The cell presentation order is the same as the orderof which cell information is described in the PGCI.

[0370] The most noticeable characteristic of the present invention liesin the original PGC. Specifically, the original PGC shows the procedureof reproducing all the video data items in the RTR_MOV.VRO of FIG. 24 insuch a manner that they are linked to each other as if they were asingle tape. Moreover, the original PGC contains not only all the videodata items in the RTR_MOV.VRO but also all the still picture informationin the RTR_STO.VRO and all the additional audio information in theRTR_STA.VRO and shows the playback procedure in such a manner that allthe pieces of information are related to each other as if they were anintegral single tape. This enables all the data items to be reproducedconsecutively.

[0371] In order to enable presentation of each cell, the cellinformation includes VOB numbers, presentation start time, andpresentation end time.

[0372] In the original PGC, each cell refers to the presentation periodof a whole VOB. So presentation start time and presentation end time ofa cell becomes equal to the presentation time of the first video pictureof the VOB and the presentation time of the last video picture of theVOB, respectively.

[0373] In order to access to a VOB recorded in a VOB file, VOBI is usedto obtain address information with respect to the file. Especially inorder to access to a middle of VOB data when a special play like timesearch is performed, VOBI includes a time map (TMAP). The TMAP is aconversion table from a given presentation time inside the associatedmovie VOB to the address of the associated VOBU inside the VOB.

[0374] When a VOB is created, it is appended at the end of the VOB fileand an associated cell and possibly an associated program is appended atthe end of the PGCI.

[0375]FIG. 25 conceptually illustrates a case where the user has changedthe cell playback sequence of the contents of the original videorecording (original PGC) later, using the user-defined PGC. For example,the video data (video object set VOBS) recorded in the audio & videodata area 1009 of FIG. 23C is composed of a collection of one or moreprogram chains PGCs.

[0376] Each PGC is a collection of programs made up of one or morecells. In what sequence which cells are to be reproduced to create aprogram can be determined by the original PGC information ORG_PGCI 2213or user-defined PGC information table UD_PGCIT 2214 of FIG. 23E.

[0377] The table TMAP in the time map information TMAPI 2243 of FIG. 23Hconverts the playback time and playback sequence of the cells specifiedin the original PGC information ORG_PGCI 2213 or user-defined PGCinformation table UD_PGCIT 2214 into addresses for VOBUs constitutingthe cells to be reproduced.

[0378] Specifically, when reproducing is done by the original PGC (thecell playback sequence in the initial video recording state), theaddresses for the VOBUs for the time zone to be reproduced via the timemap information table TMAP are determined on the basis of the contentsof the original PGC information ORG_PGCI 2213 of FIG. 23E. Then,reproducing is done in the order of the determined addresses.

[0379] On the other hand, when reproducing is done by the user-definedPGC (when the user has edited the playback sequence after videorecording), the addresses for the VOBUs for the time zone to bereproduced via the time map information table TMAP are determined on thebasis of the contents of the user-defined PGC information table UD_PGCIT2214 of FIG. 23E. Then, reproducing is done in the order of thedetermined addresses.

[0380] The cell playback sequence by the user-defined PGC informationtable UD_PGCIT 2214 may be made completely different from the cellplayback sequence by the original PGC information ORG_PGCI 2213. Theplayback time can be correlated to the addresses of the VOBUs to bereproduced, referring to the contents of the time entry and VOBU entryin the time map information TMAPI.

[0381] As shown in FIG. 26, the original PGC can be composed ofprograms. In this case, for example, programs may be divided intoprograms differing in video recording time.

[0382] The operation of reproducing the original PGC composed of movingpictures proceeds as follows:

[0383] 1. Obtain file system information by reading the disk and openthe files RTR.IFO and RTR_MOV.VRO.

[0384] 2. Read the entire file RTR.IFO into the memory and examine thePGCI.

[0385] 3. Examine file system information of the file RTR_MOV.VRO toobtain the file extents where the addresses and sizes regarding the VOBdata allocations are described.

[0386] 4. For each cell in the PCCI starting from one having theearliest cell number, get the VOBI using the VOB number associated withthe cell, and find corresponding TMAP in the VOBI in order to convertpresentation start time and presentation end time to the address offsetsin the file VRD.

[0387] 5. Start reading the VOB data from the file and perform initialbuffering until some amount of the VOB data are buffered in the trackbuffer. The initial buffering is needed whenever the reading encountersa nonseamless cell boundary.

[0388] 6. Start decoding the VOB data being buffered in the track bufferand keep reading and decoding until the cell has been completelypresented.

[0389] 7. Loop to step 5 until all of the cells in the original PGC havebeen completely presented.

[0390] Next, the program chain information PGCI contains the navigationinformation for program chains PGCs. There are two types of programchains defined in this specification, the original PGCs and user-definedPGCs. Original PGC has VOBs as well as PGCI. However, the user-definedPGC does not have its own VOBs but refer to the VOBs in the originalPGC.

[0391] As shown in FIG. 27, the program chain information PGGI includesPGC general information PGC_GI, one or more pieces of programinformation PGI #1 to PGI #m, one or more cell information searchpointers CI_SRP #1 to CI_SRP #n, and one or more pieces cell informationCI #1 to CI #n.

[0392] As shown in FIG. 28, the PGI general information PGC_GI includesone byte of reservation, one byte of PG_Ns, two bytes of CI_SRP_Ns.PG_Ns describes the number of programs in the PGC. In user-defined PGCs,0 is set in PG_Ns. The maximum number of programs in the original PGC is99. The CI_SRP_Ns describes the number of cell information searchpointers in the PGC. The maximum number of cells in the PGC is 999.

[0393] As shown in FIG. 29, the program information PGI includes onebyte of reservation, one byte of PG_TY, two bytes of C_Ns, 128 bytes ofPRM_TXTI, two bytes of IT_TXT_SRPN, and 8 bytes of THM_PTRI.

[0394] The PG_TY describes the type of the program. As shown in FIG. 30,when the protect bit b7 is 0, this means that the program is notprotected. When the protect bit b7 is 1, this means that the program isprotected. When a program is in protected state, all the VOBs referredand utilized in the presentation of that program shall not betemporarily or permanently erased. The protect flag shall not be set to1 unless all the VOBs referred by this program are in normal state.

[0395] The C_Ns describes the number of cells in the program.

[0396] The PRM_TXTI describes primary text information for the program.The first 64 bytes of the 128 bytes field is used to describing primarytext in ASCII character set. If the primary text in ASCII is shorterthan 64 bytes, the remaining bytes shall filled with 00h.

[0397] The last 64 bytes of the 128 bytes field is used for describingprimary text in another character sets, like so called shift JIS or ISO8859-15. Another character set code is described in VMGI_MAT and sharedby all the primary text information in the disk. The terminal controlcodes, which take values in the range from 01h to 11h, shall not bedescribed in PRM_TXTI.

[0398] The IT_TXT_SRPN describes the number of IT_TXT_in IT_TXT whosetext data corresponds to the program.

[0399] The THM_PTRI describes thumbnail pointer information. Setting andusing the thumbnail pointer information is an optional function for bothrecorders and players. Recorders which don't have capability to handlethis information may set FFh to all eight bytes of THM_PTRI. Playerswhich don't have capability to handle this information may simplyignores the information.

[0400] As shown in FIG. 31, the THM_PTRI includes two bytes of CN andsix bytes of THM_PT. The CN describes the cell number in which thethumbnail point exists. The THM_PT describes the thumbnail point in thetarget cell. When the resume marker exists in a movie cell, the THM_PTdescribes a presentation time PTM.

[0401] When the thumbnail exists in a still picture cell, the THM_PTdescribes the still picture VOB entry number S_VOB_ENTN in thecorresponding still picture VOB group S_VOG shown in FIG. 32.

[0402] The cell information search pointer CI_SRP of FIG. 27 includesfour bytes of CI_SA as shown in FIG. 33. The CI_SA describes the startaddress of CI with RBN from the first byte in the PGCI.

[0403] The cell information CI of FIG. 27 has two types, movie cellinformation M_CI and still picture information S_CI as shown in FIG. 34.

[0404] The movie cell information M_CI is composed of movie cell generalinformation M_C_GI as shown in FIG. 35. As shown in FIG. 36, the moviecell general information M_C_GI includes one byte of reservation, onebyte of C_TY, two bytes of M_VOBI_SRPN, two bytes of C_EPI_Ns, six bytesof C_V_S_PTM, and six bytes of C_V_E_PTM.

[0405] The C_TY describes the type of the cell. As shown in FIG. 37,000b is written in three bits b7 to b5 in the C_TY1 for movie cells. TheM_VOBI SRPN describes the number of movie VOBI search pointersM_VOBI_SRPs related to the movie cells. The C_EPI_Ns describes thenumber of pieces of cell entry point information C_EPIs.

[0406] The C_V_S_PTM describes the playback start time in the PTMdescription form in the RTR. The C_V_S_PTM and C_V_E_PTM fulfill thefollowing requirements:

[0407] (1) In case of a cell in the original PGC, the C_V_S_PTM shallfall into the first four VOBUs of the corresponding VOB and theC_V_E_PTM shall fall into the last four VOBUs of the corresponding VOB.

[0408] (2) In case of a cell is in an user-defined PGC, the followingrelation has to be fulfilled:

O_C_V_S_PTM≦C_V_S_PTM≦C_V_E_PTM≦O_C_V_E_PTM

[0409] where O_C_V_S_PTM and O_C_V_E_PTM are the presentation start timeand end time of the original cell which corresponds to the VOB referredby this cell.

[0410] The O_V_E_PTM describes the presentation end time of the cell inRTR's PTM describing format.

[0411] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

1. An information recording method of recording information in files onan information storage medium, comprising the step of recording at leastone of a video file containing video information, a still picture filecontaining till picture information, and an audio file containing audioinformation, on said information recording medium.
 2. An informationrecording method according to claim 1, further comprising the step ofrecording a management file having management information on a controlmethod of reproducing the information recorded in at least one of saidvideo file, still picture file, and audio file, in a position differentfrom those of said video file still picture file, and audio file on saidinformation recording medium.
 3. An information recording methodaccording to claim 2, wherein said management information includes atleast one piece of playback sequence information having links toreproduce the information in at least one of said video file, stillpicture file, and audio file.
 4. An information recording methodaccording to claim 3, wherein said playback sequence informationindicates a playback sequence for reproducing the reproducibleinformation in at least one of said video file, still picture file, andaudio file.
 5. An information recording method according to claim 4,wherein said playback sequence information is composed of pluralprograms.
 6. An information recording method according to claim 5,wherein said management information includes information indicating thenumber of programs constituting said playback sequence information. 7.An information recording method according to claim 2, wherein theinformation in at least one of said video file, till picture file, andaudio file is divided into specific standard units, and said managementinformation includes information indicating the positions of saidstandard units recorded on said information recording medium.
 8. Aninformation recording method according to claim 2, wherein saidmanagement information includes at least one piece of playback sequenceinformation having links to reproduce the information in at least two ofsaid video file, still picture file, and audio file.
 9. An informationrecording method according to claim 3 or 8, wherein said playbacksequence information is program chain information and the information inat least one of said video file, still picture file, and audio file isdivided into cells or objects.
 10. An information recording methodaccording to claim 9, further comprising the step of setting a unique AVaddress in at least one of said video file, still picture file, andaudio file and recording address information on either said cells orobjects in said management file on the basis of the AV address.
 11. Aninformation recording method according to claim 10, wherein said AVaddress uses the first recording position of at least one of said videofile, still picture file, and audio file as the initial value and isused to set serial numbers to all the recordable/erasable areas in atleast one of said video file, still picture file, and audio file.
 12. Aninformation recording method according to claim 2, wherein saidmanagement file includes playback sequence information indicating thesequence for reproducing all the reproducible information in at leastone of said video file, still picture file, and audio file.
 13. Aninformation recording method according to claim 1, wherein at least oneof said video file, still picture file, and audio file is composed ofplural object units, in each of which an object unit begin pack has beenrecorded.
 14. An information reproducing method comprising the step of,from an information recording medium on which at least one of a videofile containing video information, a still picture file containing stillpicture information, and an audio file containing audio information anda management file having management information on a control method ofreproducing the information recorded in the file have been recorded,reproducing the information in said file on the basis of the managementinformation recorded in said management file.
 15. An informationreproducing method according to claim 14, wherein said managementinformation includes at least one piece of playback sequence informationhaving links to reproduce the information in at least one of said videofile, still picture file, and audio file.
 16. An information reproducingmethod according to claim 15, wherein said playback sequence informationindicates the sequence for reproducing the reproducible information inat least one of said video file, still picture file, and audio file. 17.An information reproducing method according to claim 16, wherein saidplayback sequence information is composed of plural programs.
 18. Aninformation reproducing method according to claim 17, wherein saidmanagement information includes information indicating the number ofprograms constituting said playback sequence information.
 19. Aninformation reproducing method according to claim 14, wherein theinformation in at least one of said video file, still picture file, andaudio file is divided into specific standard units, and said managementinformation includes information indicating the positions of saidstandard units on said information recording medium.
 20. An informationreproducing method according to claim 14, wherein said managementinformation includes at least one piece of playback sequence informationhaving links to reproduce the information in at least two of said videofile, still picture file, and audio file.
 21. An information recordingmedium comprising: at least one of a video file containing videoinformation, a still picture file containing still picture information,and an audio file containing audio information; and a management file inwhich management information including information on the playbacksequence having links to reproduce the information in said file has beenrecorded.
 22. An information recording medium according to claim 21,further comprising a backup management file for said management file inwhich information can be recorded.
 23. An information recording mediumaccording to claim 21, wherein at least one of said video file, stillpicture file, and audio file is composed of plural object units, in eachof which an object unit begin pack has been recorded.
 24. An informationstorage medium according to claim 23, wherein said object unit beginpack has time information on recording recorded in it.